A285286 - OEIS

%I #13 Apr 24 2017 10:31:30

%S 1,-1,1,-1,-3,3,-3,-4,14,-14,4,24,-44,31,37,-107,126,-4,-208,329,-175,

%T -319,777,-704,-236,1507,-1945,430,2532,-4575,2781,3236,-9301,8697,

%U 2085,-16902,21804,-5233,-26573,47225,-27047,-34332,92242,-80162,-26926,162426

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

%H Seiichi Manyama, <a href="/A285286/b285286.txt">Table of n, a(n) for n = 0..10000</a>

%t 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 *)

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

%Y Cf. A262949.

%K sign

%O 0,5

%A _Seiichi Manyama_, Apr 16 2017