A022606 - OEIS

%I #15 Apr 05 2017 09:49:43

%S 1,-11,55,-176,451,-1078,2453,-5181,10329,-19954,37455,-68135,120725,

%T -209583,357258,-598136,985072,-1599807,2565365,-4063191,6362323,

%U -9860851,15138013,-23027730,34729959,-51965067,77174735

%N Expansion of Product_{m>=1} (1+q^m)^(-11).

%H Seiichi Manyama, <a href="/A022606/b022606.txt">Table of n, a(n) for n = 0..1000</a>

%F a(n) ~ (-1)^n * 11^(1/4) * exp(Pi*sqrt(11*n/6)) / (2^(7/4) * 3^(1/4) * n^(3/4)). - _Vaclav Kotesovec_, Aug 27 2015

%F a(0) = 1, a(n) = -(11/n)*Sum_{k=1..n} A000593(k)*a(n-k) for n > 0. - _Seiichi Manyama_, Apr 05 2017

%t nmax = 50; CoefficientList[Series[Product[1/(1 + x^k)^11, {k, 1, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Aug 27 2015 *)

%K sign

%O 0,2

%A _N. J. A. Sloane_