OFFSET
0,5
LINKS
FORMULA
EXAMPLE
a(4) = 4 since there are solutions (1,1,1), (3,1,1), (1,3,1), (1,1,3).
MATHEMATICA
Table[SeriesCoefficient[EllipticTheta[2, 0, x^4]^3/(8 (1 - x)), {x, 0, n^2}], {n, 0, 48}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Nov 23 2021
STATUS
approved