A035381 - OEIS

%I #8 Aug 27 2015 06:03:35

%S 1,1,2,2,2,3,4,4,6,7,7,9,11,12,15,18,19,23,27,29,35,41,44,51,59,64,74,

%T 86,93,106,121,131,148,169,184,206,233,253,282,318,346,384,430,467,

%U 516,576,626,689,766,831,911,1010,1096,1199,1324,1435,1565,1723,1867

%N Number of partitions of n into parts 6k+1 or 6k+3.

%F a(n) ~ exp(Pi*sqrt(2*n)/3) * Gamma(1/6) / (4 * 2^(5/12) * sqrt(3) * Pi^(5/6) * n^(7/12)). - _Vaclav Kotesovec_, Aug 27 2015

%t nmax = 100; Rest[CoefficientList[Series[Product[1/((1 - x^(6k+1))*(1 - x^(6k+3))), {k, 0, nmax}], {x, 0, nmax}], x]] (* _Vaclav Kotesovec_, Aug 27 2015 *)

%K nonn

%O 1,3

%A _Olivier Gérard_