I'm reading a book called "Stalking the Riemann Hypothesis" by Dan Rockmore. I've always been interested in prime numbers but I've always thought of them as positive integers. This book talks about complex prime numbers which I had never put together before in my head and I find it fascinating (I am not a geek, I am not a geek...). One of the interesting facts Dan Rockmore mentions is that in the complex plane, 2 is NOT a prime number (1+i)(1-i)=2.

The HP-15c, HP-42, and the RPL calculators can all handle complex numbers. Is it possible to write a program to calculate and display prime complex numbers? Could it use the same algorithms as is used to display integer primes? An example program is in William C Wicks' book "HP-48 Insights Part I" (Original edition) Section 12.11.2 on pages 359 and 360 or pages 397 through 399 in the GX version.

Since complex numbers are on a plane and not a line, a different way to display complex prime numbers is shown on page 113 of the book by using the Cartesian plane and marking 'Xs' where prime numbers are shown.

Anyway, to you Math Majors this might seem like a trivial subject but it's fascinating to me so if you have any comments to share I would appreciate it. I did search through the HP Museum about this topic but I didn't see anything specific about this jump out.

Thanks for your feedback,

Gerry