A321299 Expansion of Product_{1 <= i <= j} (1 - x^(i*j)).

1, -1, -1, 0, -1, 2, 0, 2, 0, -1, 2, -1, -2, 0, 0, -4, 0, -1, 1, 0, 2, 2, 2, -1, 3, -1, 1, 6, -2, 1, -6, 1, -4, 5, -7, -5, -1, -4, -2, 6, -4, 0, 0, -2, 13, -7, 8, 2, 5, 1, 10, 2, 9, -3, -1, -1, -6, -7, 2, -5, -8, 1, -6, -17, -4, 13, -8, 1, -16, -14, 3, 7, -1, 20, -10, 13, -3, 8

Offset

0,6

Links

Seiichi Manyama, Table of n, a(n) for n = 0..10000

Formula

G.f.: Product_{k>0} (1 - x^k)^A038548(k).

Mathematica

nmax = 100; CoefficientList[Series[Product[(1 - x^k)^Floor[(DivisorSigma[0, k] + 1)/2], {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Nov 03 2018 *)

Crossrefs

Convolution inverse of A182269.

Cf. A038548, A211856, A321300.

Sequence in context: A029401 A086150 A105166 * A105783 A326819 A268189

Adjacent sequences: A321296 A321297 A321298 * A321300 A321301 A321302

Keyword

sign,look

Author

Seiichi Manyama, Nov 03 2018

Status

approved