A035380 - OEIS

%I #8 Aug 27 2015 06:02:41

%S 1,2,2,3,3,4,5,7,8,10,11,13,15,19,22,27,30,35,39,46,53,62,70,80,89,

%T 102,115,133,149,169,187,211,235,266,297,333,368,410,454,508,563,628,

%U 691,765,841,932,1027,1136,1247,1372,1502,1653,1812,1993,2179,2388

%N Number of partitions of n into parts 6k+1 or 6k+2.

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

%t nmax = 100; Rest[CoefficientList[Series[Product[1/((1 - x^(6k+1))*(1 - x^(6k+2))), {k, 0, nmax}], {x, 0, nmax}], x]] (* _Vaclav Kotesovec_, Aug 27 2015 *)

%K nonn

%O 1,2

%A _Olivier Gérard_