A372613 Number of solutions to x^2 + y^2 + z^2 + w^2 <= n, where x, y, z, w are positive odd integers.

0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 5, 5, 5, 5, 5, 5, 5, 5, 11, 11, 11, 11, 11, 11, 11, 11, 19, 19, 19, 19, 19, 19, 19, 19, 32, 32, 32, 32, 32, 32, 32, 32, 44, 44, 44, 44, 44, 44, 44, 44, 58, 58, 58, 58, 58, 58, 58, 58, 82, 82, 82, 82, 82, 82, 82, 82, 100, 100, 100, 100, 100, 100, 100, 100

Offset: 0

Author

Ilya Gutkovskiy, May 07 2024

Keywords

• nonn

Links

• Index entries for sequences related to sums of squares

Crossrefs

Cf. A008438, A046895, A224213, A349611, A372511, A372512.

Programs

Mathematica

nmax = 75; CoefficientList[Series[EllipticTheta[2, 0, x^4]^4/(16 (1 - x)), {x, 0, nmax}], x]