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%I #16 Mar 28 2017 14:48:13
%S 1,0,1,0,1,0,1,0,1,1,1,1,1,1,1,1,2,1,3,1,3,1,3,2,3,3,3,4,3,4,4,4,6,4,
%T 7,4,8,5,8,7,8,9,8,10,9,11,12,11,15,11,17,12,18,15,19,19,19,22,20,24,
%U 24,25,29,26,34,27,37,31,39,38,40,44,42,49,47,52,55,54,64,56,71,62,76,72,79
%N Number of partitions of n into parts each equal to 2 mod 7.
%H Vaclav Kotesovec, <a href="/A109704/b109704.txt">Table of n, a(n) for n = 0..10000</a>
%F G.f.: 1/product(1-x^(2+7j), j=0..infinity). - _Emeric Deutsch_, Apr 14 2006
%F a(n) ~ Gamma(2/7) * exp(Pi*sqrt(2*n/21)) / (2^(23/14) * 3^(1/7) * 7^(5/14) * Pi^(5/7) * n^(9/14)) * (1 + (11*Pi/(168*sqrt(42)) - 9*sqrt(3/14)/(7*Pi)) / sqrt(n)). - _Vaclav Kotesovec_, Feb 27 2015, extended Jan 24 2017
%F a(n) = (1/n)*Sum_{k=1..n} A284443(k)*a(n-k), a(0) = 1. - _Seiichi Manyama_, Mar 28 2017
%e a(18)=3 because we have 18=16+2=9+9=2+2+2+2+2+2+2+2+2.
%p g:=1/product(1-x^(2+7*j),j=0..20): gser:=series(g,x=0,87): seq(coeff(gser,x,n),n=0..84); # _Emeric Deutsch_, Apr 14 2006
%t nmax=100; CoefficientList[Series[Product[1/(1-x^(7*k+2)),{k, 0, nmax}], {x, 0, nmax}], x] (* _Vaclav Kotesovec_, Feb 27 2015 *)
%K nonn
%O 0,17
%A _Erich Friedman_, Aug 07 2005
%E Changed offset to 0 and added a(0)=1 by _Vaclav Kotesovec_, Feb 27 2015