0,5

a(n) is the number of representations of n as a sum of n squares of nonnegative integers.

Seiichi Manyama, Table of n, a(n) for n = 0..500

a(n) = [x^n] (1 + theta_3(x))^n/2^n, where theta_() is the Jacobi theta function. - Ilya Gutkovskiy, Jan 17 2018

Cf. A045847.

Sequence in context: A203233 A112561 A303170 * A143567 A147375 A147216

Adjacent sequences: A287614 A287615 A287616 * A287618 A287619 A287620

nonn

Seiichi Manyama, May 28 2017

approved