A327686 Expansion of Product_{k>=1} 1/(1 + x^k/(1 + x^(2*k)/(1 + x^(3*k)))).

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

Links

Table of n, a(n) for n=0..76.

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

Cf. A307757, A327688.

Sequence in context: A086965 A256572 A025463 * A274472 A283669 A220945

Adjacent sequences: A327683 A327684 A327685 * A327687 A327688 A327689

Keyword

sign

Author

Seiichi Manyama, Sep 22 2019

Status

approved