A320245 G.f.: Product_{k>=1, j>=1} 1/((1 + x^(k*j)) * (1 - x^(k*j))^2).

1, 1, 4, 6, 17, 25, 59, 89, 187, 284, 545, 828, 1505, 2270, 3930, 5904, 9861, 14695, 23827, 35248, 55775, 81882, 126874, 184870, 281467, 407065, 610193, 876282, 1295892, 1848144, 2700398, 3825912, 5530337, 7786022, 11145541, 15597196, 22131170, 30792303

Offset

0,3

Comments

Convolution of A288007 and A320236.

Links

Vaclav Kotesovec, Table of n, a(n) for n = 0..10000

Mathematica

nmax = 50; CoefficientList[Series[Product[1/((1+x^(k*j))*(1-x^(k*j))^2), {k, 1, nmax}, {j, 1, Floor[nmax/k]+1}], {x, 0, nmax}], x]

Crossrefs

Cf. A158441, A320236, A320238.

Sequence in context: A343758 A024305 A342231 * A337208 A034492 A125691

Adjacent sequences: A320242 A320243 A320244 * A320246 A320247 A320248

Keyword

nonn

Author

Vaclav Kotesovec, Oct 08 2018

Status

approved