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A306691
Expansion of Product_{k>=1} (1 + x^k * (1 - x)).
2
1, 1, 0, 1, -1, 1, 0, -1, 1, 0, 0, -2, 4, -4, 3, -2, 0, 2, -1, -2, 3, -1, -3, 8, -11, 10, -8, 9, -13, 15, -9, -2, 6, 2, -14, 21, -20, 10, 8, -25, 29, -22, 20, -31, 46, -53, 48, -33, 15, -9, 27, -57, 71, -62, 53, -63, 83, -87, 53, 16, -80, 91, -47, 3, -19, 99, -186, 219, -184
OFFSET
0,12
LINKS
FORMULA
G.f.: exp(Sum_{k>=1} x^k * Sum_{d|k} (-1)^(d+1)*(1 - x)^d/d). - Ilya Gutkovskiy, Apr 16 2019
MATHEMATICA
With[{nn=70}, CoefficientList[Series[Product[1+x^k (1-x), {k, nn}], {x, 0, nn}], x]] (* Harvey P. Dale, Aug 03 2020 *)
PROG
(PARI) N=66; x='x+O('x^N); Vec(prod(k=1, N, 1+x^k*(1-x)))
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Apr 16 2019
STATUS
approved