OFFSET
0,5
COMMENTS
Partial sums of A280542.
LINKS
Eric Weisstein's World of Mathematics, Jacobi Theta Functions
FORMULA
G.f.: 1/((1 - x)*(1 - Sum_{k>=2} x^(k^2))).
MATHEMATICA
nmax = 62; CoefficientList[Series[2/((1 - x) (3 + 2 x - EllipticTheta[3, 0, x])), {x, 0, nmax}], x]
nmax = 62; CoefficientList[Series[1/((1 - x) (1 - Sum[x^k^2, {k, 2, nmax}])), {x, 0, nmax}], x]
a[0] = 1; a[n_] := a[n] = Sum[Boole[IntegerQ[k^(1/2)] && k != 1] a[n - k], {k, 1, n}]; Accumulate[Table[a[n], {n, 0, 62}]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, May 15 2018
STATUS
approved