A333045 Expansion of Product_{k>=1} (1 + x^sigma(k)) / (1 - x^sigma(k)).

1, 2, 2, 4, 8, 10, 14, 24, 34, 44, 62, 86, 116, 156, 206, 274, 362, 462, 598, 782, 994, 1258, 1606, 2018, 2528, 3178, 3952, 4904, 6094, 7490, 9194, 11322, 13834, 16836, 20518, 24880, 30086, 36366, 43792, 52656, 63250, 75626, 90344, 107926, 128422, 152546

Offset

0,2

Comments

Convolution of A111865 and A305321.

Links

Table of n, a(n) for n=0..45.

Mathematica

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

Crossrefs

Cf. A000203, A111865, A305321.

Sequence in context: A085619 A085620 A325867 * A050047 A056381 A245597

Adjacent sequences: A333042 A333043 A333044 * A333046 A333047 A333048

Keyword

nonn

Author

Vaclav Kotesovec, Mar 06 2020

Status

approved