A285286 Expansion of Product_{k>=0} 1/(1 + x^(3*k+1))^(3*k+1).

1, -1, 1, -1, -3, 3, -3, -4, 14, -14, 4, 24, -44, 31, 37, -107, 126, -4, -208, 329, -175, -319, 777, -704, -236, 1507, -1945, 430, 2532, -4575, 2781, 3236, -9301, 8697, 2085, -16902, 21804, -5233, -26573, 47225, -27047, -34332, 92242, -80162, -26926, 162426

Offset: 0

Author

Seiichi Manyama, Apr 16 2017

Keywords

• sign

Links

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

Crossrefs

Product_{k>=0} 1/(1 + x^(m*k+1))^(m*k+1): A284628 (m=2), this sequence (m=3), A285287 (m=4).

Cf. A262949.

Programs

Mathematica

nmax = 50; CoefficientList[Series[Product[1/(1 + x^(3*k-2))^(3*k-2), {k,1,nmax}], {x,0,nmax}], x] (* Vaclav Kotesovec, Apr 16 2017 *)