The following is true:

COMB(n, 2) + n = Sum of all integers from 1 to n

i.e. if n = 5

COMB(5, 2) + 5 = 5! ÷ (3!*2!) + 5 = 10 + 5 = 15

and

1 + 2 + 3 + 4 + 5 = 15

However, when I input

'COMB(5,2) + 5' on one level,

and '[Capital Sigma symbol](X=1,5,X)' on the other,

and I execute the == command on the Program-Test Menu, I get a 0 as a result (incorrect result)

Both objects inputed are same type (9 - algebriac expressions?).

A bug in the 49g+ CAS perhaps.