OFFSET
0,5
FORMULA
EXAMPLE
a(4) = 3 since there are solutions (1,1), (3,1), (1,3).
MATHEMATICA
Table[SeriesCoefficient[EllipticTheta[2, 0, x^4]^2/(4 (1 - x)), {x, 0, n^2}], {n, 0, 55}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Nov 23 2021
STATUS
approved