A281154 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

A281154

Expansion of (Sum_{k>=2} x^(k^2))^2.

0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 2, 0, 0, 0, 0, 1, 0, 2, 0, 0, 0, 0, 2, 0, 0, 0, 2, 0, 0, 1, 0, 2, 0, 0, 0, 0, 0, 2, 2, 0, 0, 0, 2, 0, 0, 0, 0, 1, 0, 2, 2, 0, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0, 2, 0, 0, 2, 0, 0, 0, 1, 2, 2, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 4, 0, 0, 0, 2, 2, 0, 0, 0, 0, 0, 0, 2, 1, 0, 2, 0, 0, 0, 2

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,14

COMMENTS

Number of ways to write n as an ordered sum of 2 squares > 1.

LINKS

Table of n, a(n) for n=0..104.

Index entries for sequences related to sums of squares

FORMULA

G.f.: (Sum_{k>=2} x^(k^2))^2.

G.f.: (1/4)*(1 + 2*x - theta_3(0,x))^2, where theta_3 is the 3rd Jacobi theta function.

EXAMPLE