A046898 Partial sums of A046897.

1, 4, 8, 11, 17, 29, 37, 40, 53, 71, 83, 95, 109, 133, 157, 160, 178, 217, 237, 255, 287, 323, 347, 359, 390, 432, 472, 496, 526, 598, 630, 633, 681, 735, 783, 822, 860, 920, 976, 994, 1036, 1132, 1176, 1212, 1290, 1362, 1410, 1422, 1479, 1572, 1644, 1686, 1740, 1860

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

Links

• Wikipedia, Jacobi four square theorem

Crossrefs

Cf. A046897.

Programs

Mathematica

Accumulate[DivisorSum[#1, # &, Mod[#, 4] != 0 &] & /@ Range[50]] (* Jayanta Basu, Jun 30 2013 *)

PARI

my(N=60, q='q+O('q^N)); Vec(sum(k=1, N, k*q^k/(1+(-q)^k))/(1-q)) \\ Seiichi Manyama, Jun 21 2024

Formula

G.f.: 1/(1 - q) * Sum_{k>=1} k * q^k / (1 + (-q)^k). - Seiichi Manyama, Jun 21 2024

Extensions

Offset changed from 0 to 1 by Seiichi Manyama, Jun 21 2024