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A327686
Expansion of Product_{k>=1} 1/(1 + x^k/(1 + x^(2*k)/(1 + x^(3*k)))).
3
1, -1, 0, 0, -1, 0, 1, 0, 0, 0, -1, 0, 2, 0, 0, -1, 0, 1, 0, -2, -2, 4, 1, 0, 1, -6, 2, 3, -2, -2, -2, 2, 3, 2, -1, -3, 3, -1, -1, 0, -7, 3, 7, -4, 0, 1, -1, 3, 4, -5, -3, 5, -3, -3, 5, -3, 0, 3, -8, -3, 11, -3, 1, 7, -5, 12, -2, -17, -3, 5, 9, -12, 6, -12, -1, 34, -26
OFFSET
0,13
MATHEMATICA
m = 76; CoefficientList[Series[Product[1/(1 + x^k/(1 + x^(2*k)/(1 + x^(3*k)))), {k, 1, m}], {x, 0, m}], x] (* Amiram Eldar, May 06 2021 *)
PROG
(PARI) N=66; x='x+O('x^N); Vec(1/prod(k=1, N, 1+x^k/(1+x^(2*k)/(1+x^(3*k)))))
CROSSREFS
Sequence in context: A086965 A256572 A025463 * A274472 A283669 A220945
KEYWORD
sign
AUTHOR
Seiichi Manyama, Sep 22 2019
STATUS
approved