50th birthday !


Hi all,

    Just perchance, today happens to be my 50th birthday, so it stands to reason that I've also completed my 5th decade, 10th lustrum, and 1st half-century (!), all in one go ... How's that for efficiency ? :-)

    If you lived in my area I'd buy you dinner so that we could commemorate the event amidst an enjoyable conversation about calcs, math, life, and everything. Failing that, I've uploaded a number of freely downloadable materials to my calc web site, namely two new articles and six additional past "Short & Sweet Math Challenges", all of them in glorious PDF format. Details:

    • New articles online:

      • Long Live the HP-71B !

          This is a 12-page affair which includes two wonderful photographs, as well as a brand-new program I've written specifically for it, which in just 6 lines of code (!) manages to generate and print user-defined stereograms, easily viewable from the printed page or monitor output (Emu71 or HP-IL monitor) in full, glorious 3-D !

          Three sample generated stereograms are included, one of them being a 3-D HP logo :-)

      • Boldly Going ... - Going Back to the Roots

          Finding complex roots of complex equations is a complex business
          Most specially when the built-in Solver won’t do it per se. Though the HP35s
          includes pretty decent complex number handling you can’t generally use the
          built-in Solver to find complex roots of arbitrary equations.

          This small HP35s program finds a real or complex root of an arbitrary equation with real and/or complex coefficients starting from just one real or complex initial guess. The program typically converges very quickly to a root with speed comparable to that of the built-in Solver and will foray into the complex domain if need be, even starting from a real initial guess.

    • Additional "Short & Sweet Math Challenges" online:

      • S&SMC #10: Counting Beans

      • S&SMC #11: Who's Next ?

      • S&SMC #12: Squaring Cubes

      • S&SMC #13: Adding up to Infinity

      • S&SMC #14: Cooking Conjectures

      • S&SMC #15: Spring 2006 Special

    That's all. I hope you'll enjoy them and in any case, have a nice day. I fully intend to ! :-)

Best regards from V.



Happy birthday and many, many more!

Very respectfully,



Happy birthday, Valentin!
And thank you for your involvement with the HP calc stuff, it's a pleasure to read your posts and articles. Keep up the good work.
Best wishes:

Edited: 5 Mar 2008, 9:16 p.m.


Happy birthday Valentin, hopefully you had a fun and illustrious evening with friends, enjoying some Rioja!

I'm already looking forward to all the things I will learn directly and indirectly from you over the second halve of your stint on earth!!




Hi, PeterP:

    Thanks a lot for your kind wishes and appreciation, but "second halve of your stint on earth" !?

    I'd agree with the "second halve" of my 1st century, but that's about it, your implications are a bit pessimistic ... ;-)

Best regards from V.



It was meant exactely as you (hopefully interpreted it, knowing my appreciation for your patience and continuous advice) - in Austria we sometimes say for someone getting 30 "Na, jetz hast schon mal das erste viertel gut ueberstanden" (which means someting like - good job in the first quarter). For someone getting 40 it becomes "das erste drittel" (the first third) and for someone getting 50 - alas, the first halve.

Please forgive my clumsy attempt to translate a very well meant austrian wish, which obviously did not quite work.

I should have just sticked with: Happy Birthday! ;-)




Happy birthday, Valentin. Mine was yesterday (the 4th), but I'm a meer 45. All I could find about my age is...

Forty-five is a triangular number, a hexagonal and 16-gonal number, a Kaprekar number, and a Harshad number.

45 is the sixth positive integer with a prime factorization of the form p^2 q, with p and q being prime.

33 is the aliquot sum of 45 and the aliquot sequence of 45 is (45,33,15,9,4,3,1,0) (...whatever that is....)




Ola Valentin y feliz cumpleaños!!

Please accept my best wishes and thanks for your efforts to continuously feeding the HP fans community with your challenges and contributions.

Cordiales saludos and enjoy this day!


P.S.: and now...let's go to your webpage to download the materials you kindly made available :)


Hi, Giancarlo:

Giancarlo posted:

    "and now...let's go to your webpage to download the materials you kindly made available :)"

      That's exactly the idea. I hope you'll enjoy them, any and all comments welcome.

    Thank you very much for your kind wishes and appreciation and

Best regards from V.

2 OPTION BASE 0 @ DESTROY ALL @ DIM A$[79] @ L=0 @ DIM E$[435] @ N=0
4 INTEGER Z(1610) @ C=1610 @ D=0 @ E=10000 @ F=100000 @ H=0
6 B=C @ C=C-1 @ IF B<=1523 THEN 20
8 B=B-1 @ IF B=0 THEN 14
12 Z(B)=MOD(D,B) @ D=FLOOR(D/B) @ GOTO 8
14 H=5 @ X=E+FLOOR(D/F) @ DISP "."; @ D=MOD(D,F) @ E=D @ N=N+5
16 FOR I=1 TO 5 @ E$[N-I+1,N-I+1]=STR$(MOD(X,10)) @ X=FLOOR(X/10) @ NEXT I
18 GOTO 6
20 N=1 @ FOR I=1 TO 100 @ READ A @ FOR J=1 TO 16 @ L=L+1
22 IF L=80 THEN 28
24 IF MOD(A,2)=1 THEN A$=A$&E$[N,N] @ N=N+1 ELSE A$=A$&" "
26 A=INT(A/2) @ NEXT J
28 IF MOD(I,5)=0 THEN DISP A$ @ A$="" @ L=0
34 DATA 0,0,0,0,0,58124,61936,1561,0,0,58124,13104
36 DATA 795,0,0,45446,6937,435,0,0,45446,6937,435,0
38 DATA 0,39422,63993,241,0,0,39302,6169,96,0,0,64902
40 DATA 6169,96,0,0,3267,3087,48,0,0,1731,3087,48
42 DATA 0,0,0,0,0,0,0,0,60540,28615,2008,24974
44 DATA 0,27852,25356,3288,12686,0,14022,12684,6252,6939,0,14022
46 DATA 12684,6252,6939,0,63038,61831,39023,3865,0,14022,12675,39020
48 DATA 1561,0,14022,12675,52284,1567,0,7107,6342,52790,816,0
50 DATA 7039,6342,25590,816

Edited: 6 Mar 2008, 3:17 a.m.


Hi, Egan:

    Why, thank you !!! :-)

      I really appreciate that you took the time and effort to post this Greetin' Program, most specially as it's written specifically for the HP-71B ! It almost moves me to tears ... 8~)

      For those interested, when run Egan's program prints the following (on a physical (or emulated: Emu71) HP-IL monitor:



      27 18 281 82845 90452 35 36
      02 87 471 35 26 62 49 77 57
      24 70 93 69 99 59 57 49 66 96
      76 27 72 40 76 63 03 53 54 75
      94571382 17 85 251664 274274 6639
      19 32 00 30 59 92 18
      17 41 3596629 04 35 72
      90 03 34 2952 60 59
      56 30 73 8132 32 86

      27943 49 076323 382988 07 53 19525 101 90 11
      57 38 34 18 79 30 70 21 54 08 914 99 34
      88 41 67 50 92 44 76 14 60 66 80 82 26 48
      00 16 84 77 41 18 53 74 23 45 44 24 37 10
      75390 77 7449920 69 55170276 18 38 60 62 6133
      13 84 58 30 00 75 20 44 93 38 26 56 02
      97 60 67 37 11 32 00 7093 28 7091274 43
      74 7047 23 06 96 97 72 09 310 14 16 92
      8368190 25 51 51 08 65 74 637721 11 25 23

      which are the first 433 decimal digits of e (=2.71828...) arranged to form the slanted letters of "HAPPY BIRTHDAY".

      Lines 4-18 go on about computing that multiprecision value of e using a very simple (if not particularly efficient) algorithm (but who cares ?), then lines 20-32 display the value so as to form the slanted letters of the "HAPPY BIRTHDAY" greeting text. The DATA statements at lines 34-50 are the raster definitions for the text's pixels, notice for instance the first five '0' at the beginning of line 34 ("HAPPY" does have five characters) and the eight '0' at the beginning of line 42 ("BIRTHDAY" has eight characters), i.e.: a first blank raster line used for spacing.

    Again, thanks a lot, very much appreciated as it perfectly combines my love for math, HP-71B programming, surprise, and beautiful aesthetics. What more could anyone ask from a birthday's greeting ? :-)
Best regards from V.

Here in the Netherlands that's what some of us use to say when a colleague or someone alike is entering the group of 50+ agers. Of course it can only be said by a person already in this group ;-)

Many happy returns, and have a very nice day.



I am not there yet, but getting very close ....


Feliz cumpleaños, Valentin, y muchos más! I apologize for continuing staying ahead of you in this measure (not my merit, of course ;), however, you are far beyond me mathematically and in your knowledge of calculadores HP. Keep up your fine publishing!

All the best to you and your family!

Edited: 6 Mar 2008, 6:10 a.m.


Happy Birthday to you Valentin,

... and ad multos annos ( a very Long Life ahead ).

Congratulations and thank you for both Articles on your Calc Web Site.

Again Congratulations, and Best Regards from


PS : And if we had to keep going by Numbers, I was borne on 17-01-53 ( or : 53-01-17 for the english speaking community ) which is a " Magic " date since, as everybody knows, the 17 th Prime Number is 53 .


Have a happy one and may there be many more!


Even if this is the day after, I want to join those who congratulated, because you're a very good friend, here at the MoHPC.

Happy birthday!

-- Antonio


I hope your 2nd half century is even more fun than the first half century!!!



Hi, Mad Dog ebaycalcnut:

Mad Dog ebaycalcnut posted:

"I hope your 2nd half century is even more fun than the first half century!!! HAPPY BIRTHDAY!!!"

    Thank you very much for your kind wishes but I seriously doubt I'll have more fun than in the first half: I've done so many weird and varied things in those 50 years, when in prime physical condition, that there's no way I can surpass that.

    Not that I'd want either: too adventurous and frequently dangerous :-)

    Nevertheless you'd be surprised to know that there's still some fire left from those hazardous times: one of my most cherished birthday presents it's been a US $15,000 nihonto ! ... Not bad for a math-oriented HP calculator freak, uh ? :-)

Best regards from V.


...I seriously doubt I'll have more fun than in the first half: I've done so many weird and varied things in those 50 years, when in prime physical condition, that there's no way I can surpass that.

Doubt not! Here is someone who's still more active and creative than ever, having recently completed his second half:


Best regards,



Happy birthday and many happy returns of the day!

This (possibly) confirms a suspicion I had regarding the solutions to your Valentine’s Day challenge. I was successful in implementing a solution on my 35s. (I did not post it because it seemed pretty trivial compared to the analyses and programs presented by others in that thread.) Upon solving the first set of numbers, I noted that the solution did not appear to consist of random numbers. I took some guesses at where they came from as follows:

Sum Set 1) 
3734, 3768, 284, 3950, 466, 4000, 516, 500, 3966, 3784

Solution numbers and guesses at origins:
-1492 negative of the year that Columbus first travelled to the Americas (any meaning to the negative sign?)
1776 US declared independence from Great Britain
1958 Valentin’s birth year?
1992 Laura’s birth year?
2008 now

The second set also did not appear to be random, as follows:
Sum Set 2)
-0.4233, -1.7274, -2.4485, -0.9055, 4.1325, 3.4114, 4.9544, 2.1073, 3.6503, 2.9292

Solution numbers and guesses at origins:
-3.1416 negative of Pi rounded to four decimal places (why negative?)
0.6931 logarithm of 2 to base e rounded to four decimal places
1.4142 square root of 2 rounded to four decimal places
2.2361 square root of 5 rounded to four decimal places
2.7183 e rounded to four decimal places

I was unable to come up with any guesses for the solutions to the remaining three sets of sums. Were there any, or am I attempting to discover meaning where none existed?

Best regards,



Hi, Jeff:

Jeff posted:

    "This (possibly) confirms a suspicion I had regarding the solutions to your Valentine’s Day challenge."

      Absolutely. Your intuition was right on the spot. All meanings you attributed to the year-like and the math-constants-like numbers are exact, down to my birth year and Laura's.

      As for 1492 and 3.1416 appearing with a minus sign, it has no special meaning. I only did it to make the solutions slightly harder to guess by trial and error. The remaining three sets of solutions lack also any special meaning as far as I'm concerned.

    Thanks for your kind wishes and appreciation, congratulations for your keen intuition, and

Best regards from V.


Happy birthday, Valentin!

I wish I were living in your neighbourhood. Because I don't, I had to call the local pizza service. ;-)

I wish you the very best! I had much fun with those of your S&SMCs which appeared while I had the time to tackle them. Spare time varies over time. I hope your next challange comes at the right moment.

Celebrate this day; enjoy every other day to come!



Hi, Marcus:

Marcus posted:

    "I wish I were living in your neighbourhood."

      The feeling is mutual, I'm sure you would make a very fine companion for dinner and you'd also enjoy my close friends' company: quite an interesting, HP-calc loving bunch. We've known each other for longer than 30 years and still going strong.

    "I hope your next challange comes at the right moment."

      I hope so. Barring unforeseen circumstances, it will appear exactly next April 1st, as an "Spring Special" and I can promise it will provide challenge enough for everyone, from the novice at HP calc programming to such high-powered individuals as Egan and yourself, to name a few.

    Thanks a lot for your kind wishes and appreciation, and

Best regards from V.


Albeit beeing already TWO days behind (local German time), I hope you won't mind still getting the Very Best Wishes for Your next 50 years - at least 50 years I mean ... ;-))

Respectfully Yours,

Peter A. Gebhardt

Edited: 6 Mar 2008, 7:47 p.m.


Hi, Peter:

Peter posted:

    "Albeit beeing already TWO days behind (local German time), I hope you won't mind still getting the Very Best Wishes for Your next 50 years - at least 50 years I mean ... ;-))"

      Of course I don't mind, you're more than welcome, the more "Best Wishes" the merrier :-)

    Thank you very much for your kind wishes, and

Best regards from V.


Hi, all:

    Thank you very much to all of you who took the trouble to post your best wishes for my 50th birthday.

    I would love to individually reply to each and every post and indeed I've tried, but it's already 2:05 AM in the night and tomorrow I have a long day of critically important hard work to do so I need to rest in order to be in decent shape.

    Nevertheless be assured that I've read and appreciated very much each and every individual post, you really made my day.

Best regards from V.


HaPpy birthday, Valentin!

Sorry if I am a bit late, it's just that I've been away for a while.

I have noticed you have received 16 birthday compliments so far. Though I was tempted to wait to give you the 71st one, I am glad to be number 17 instead :-)

Yours is the birthday and yet we keep on receiving gifts! Thank you very much!



Happy birthday! Happy HP-50Y!


Hi all:

    I've noticed that some of you did send a private message, either via this MoHP Forum contact facilities or else by sending an e-mail to my public e-mail address featured in my calc web page.

    I thank you all who did just that, but some of you forgot to add the "HP CALCS" string to your message (which is absolutely understandable, people do it all the time) and
    I just had the sheer luck of finding fifteen (!) such e-mails sent to the trash bin by the spam filter, just before they got trashed (so I was able to read and reply to them. :-).

    If you did send me some message and I haven't replied already, chances are your message got trashed, most regrettably. Simply resending it with "HP CALCS" somewhere in the body or the subject of the message would solve the problem.

    Sorry for the inconvenience, I don't want you to think that I gave your kind message a miss, it's just that I didn't have the chance to see it in the first place.

Best regards from V.


My best wishes :)
It shows real dedication to post on your birthday :)


Happy (I/II)C (Roman numerals) Anno, Valentin!


dona nobis pacem


Heres a calculator site I ran across in the RF cafe site.
Enjoy, Sam http://www.martindalecenter.com/Calculators2_3_Unit.html#COMP-ALL


Hi, Valentin --

And a somewhat-belated greeting and best wishes from me. You'd mentioned your age several times in posts over the past few years, so I wasn't taken by surprise. Of course, most of us in theis group are over 40...

Like "Jeff O.", I too had noticed the significance of the numbers in your recent challenge, figuring 1958 to be your birth year. However, I took 1992 to mean "The Year of Spain", as one governmental tourism-promotion office called it in 1989: 500th anniversary of Columbus' voyage; the Summer Olympics in Barcelona; perhaps also an EU milestone. (Of course, the actual significance of "1992" was much more personal...)

Best regards,

-- KS


Hello Valentin,

better late, than never: Happy Birthday!

Best wishes, Max


Thanks a lot for your greeting and kind wishes, much appreciated !

As for 1992, it was important to me because of my daughter's birth and because of "Tubular Bells II" being released (matter of fact, I used to rock her craddle while quietly listening to it).

Other events of that year didn't even register with me.

:-) :-)

Best regards from V.



Please receive this delayed, but deeply meant, birthday greeting. I tried, with little success, to bring some extra content to this post, but there were no great discoveries or news to include. I just noted that “50” (decimal), converted to “heptal” (base 7, anybody uses it?) is “71”, an important number for the HP-region of your heart. To apply the same idea to “15”, another number cherished by you, we should resort to base 45, which seems even more bizarre!

By the way, I will be reaching that same waypoint in a few weeks. In fact, the “DeltaDays” function will show a difference of 43 days between our respective birthdays. While there is no HP-43 (yet…), is interesting to see that “43” is the exact midpoint between “15” and “71”.

My sincere best wishes for you in this new stage of your life.


Hi, Andrés:

    Thank you very much for your kind wishes, they're really
    much appreciated indeed ! :-)

    However, there's something I'd like to humbly comment:

      "I just noted that “50” (decimal), converted to “heptal” (base 7, anybody uses it?) is “71”"

        Er, no ... However much I'd like it to be "71", the fact is "50" in base 7 is "101", not "71". Base-7 digits are 0,1,2,3,4,5, and 6 ... :-\ ... but who cares ? Intention is what counts ! :-)

    Thanks again and

Best regards from V.


You are right, of course... I started with a first approach in base 8 (which of course has a 71, but certainly not equal to 50 decimal but to 57...), then played a little with the fact that 50 = 7^2 + 1^2... and then messed it all in a wrong statement! Shame on me!!

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