To show that

(1) it is possible to express n! as the difference of two perfect squares for all positive integers except n = 2 and n = 3, that is

n! = a^2 - b^2

(2) whether it is possible to express n! as the sum of two squares, that is

n! = a^2 + b^2

See sequence A138196 http://oeis.org/A138196

## No comments:

## Post a Comment