A283238 Expansion of exp( Sum_{n>=1} sigma_2(3*n)*x^n/n ) in powers of x.

1, 10, 75, 447, 2335, 10977, 47667, 193775, 745819, 2738568, 9653342, 32821384, 108061167, 345622069, 1076767956, 3275039352, 9743874779, 28405248949, 81256123017, 228383836091, 631427595230, 1718990010867, 4612234492354, 12206598044861, 31889379237288

Offset: 0

Author

Seiichi Manyama, Mar 03 2017

Keywords

• nonn

Links

• Seiichi Manyama, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. exp( Sum_{n>=1} sigma_k(3*n)*x^n/n ): A182819 (k=1), this sequence (k=2).

Cf. exp( Sum_{n>=1} sigma_2(m*n)*x^n/n ): A000219 (m=1), A283224 (m=2), this sequence (m=3).

Formula

a(n) = (1/n)*Sum_{k=1..n} sigma_2(3*k)*a(n-k). - Seiichi Manyama, Mar 04 2017