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%I #5 Mar 30 2012 18:37:37
%S 1,2,3,6,8,15,21,34,47,74,99,151,201,287,383,540,701,970,1255,1688,
%T 2171,2882,3657,4801,6058,7819,9816,12566,15619,19826,24540,30812,
%U 37950,47319,57901,71769,87435,107525,130482,159660,192721,234633,282240,341656,409549
%N G.f.: 1/(1-x) = Sum_{n>=0} a(n)*x^n*Product_{k=1..n+1} (1-x^k).
%e G.f.: 1/(1-x) = 1*(1-x) + 2*x*(1-x)*(1-x^2) + 3*x^2*(1-x)*(1-x^2)*(1-x^3) + 6*x^3*(1-x)*(1-x^2)*(1-x^3)*(1-x^4) + 8*x^4*(1-x)*(1-x^2)*(1-x^3)*(1-x^4)*(1-x^5) +...
%o (PARI) {a(n)=local(A=[1]); for(i=1,n+1, A=concat(A,0); A[#A]=1-polcoeff(sum(m=1, #A, A[m]*x^m*prod(k=1,m, 1-x^k +x*O(x^#A) )), #A) ); A[n+1]}
%o for(n=0,50,print1(a(n),", "))
%Y Cf. A126796.
%K nonn
%O 0,2
%A _Paul D. Hanna_, Mar 08 2012
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