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A309575
Expansion of Product_{k>=1} (1 - (x*(1 + x))^k).
0
1, -1, -2, -2, -1, 1, 5, 11, 17, 26, 36, 35, 20, -5, -65, -221, -510, -897, -1379, -2157, -3498, -5225, -6500, -6425, -4775, -1463, 5951, 25905, 74833, 173129, 334719, 563200, 876876, 1363232, 2208921, 3621969, 5631470, 7896109, 9725768, 10374574, 9340382, 6104500, -1413334
OFFSET
0,3
FORMULA
G.f.: exp(-Sum_{k>=1} sigma(k)*(x*(1+x))^k/k).
MATHEMATICA
nmax = 40; CoefficientList[Series[Product[(1 - (x*(1+x))^k), {k, 1, nmax}], {x, 0, nmax}], x] (* Vaclav Kotesovec, Sep 22 2019 *)
PROG
(PARI) N=66; x='x+O('x^N); Vec(prod(k=1, N, 1-(x*(1+x))^k))
(PARI) N=66; x='x+O('x^N); Vec(exp(-sum(k=1, N, sigma(k)*(x*(1+x))^k/k)))
CROSSREFS
Convolution inverse of A238441.
Sequence in context: A177694 A092450 A279629 * A014291 A136587 A136247
KEYWORD
sign
AUTHOR
Seiichi Manyama, Sep 21 2019
STATUS
approved