login
Number of partitions of n into parts 7k+2 or 7k+6.
0

%I #8 Aug 26 2015 06:49:41

%S 0,1,0,1,0,2,0,2,1,2,1,3,2,3,3,4,3,6,4,7,5,9,6,11,8,13,11,15,14,18,17,

%T 22,21,26,25,33,29,39,36,46,43,55,52,63,64,74,75,88,89,103,104,122,

%U 121,144,142,167,167,193,196,224,229,258,268,298,309,347,356,400,412

%N Number of partitions of n into parts 7k+2 or 7k+6.

%F a(n) ~ exp(2*Pi*sqrt(n/21)) * Gamma(2/7) * Gamma(6/7) / (4 * 3^(9/28) * 7^(5/28) * Pi^(6/7) * n^(23/28)). - _Vaclav Kotesovec_, Aug 26 2015

%t nmax = 100; Rest[CoefficientList[Series[Product[1/((1 - x^(7k+2))*(1 - x^(7k+6))), {k, 0, nmax}], {x, 0, nmax}], x]] (* _Vaclav Kotesovec_, Aug 26 2015 *)

%K nonn

%O 1,6

%A _Olivier GĂ©rard_