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%I #7 Jul 04 2013 15:45:00
%S 1,1,2,5,12,29,71,175,438,1125,2961,7887,20949,54892,141198,357068,
%T 895592,2267345,5937586,16445988,48475348,149753749,472130021,
%U 1482046059,4556113875,13598311459,39278316217,109829580639,298021031162,787853185200,2039529355219,5201580347276
%N G.f.: Sum_{n>=0} x^n / (1-x)^sigma(n).
%C Here sigma(n) equals the sum of divisors of n (A000203).
%H Paul D. Hanna, <a href="/A227237/b227237.txt">Table of n, a(n) for n = 0..720</a>
%e G.f.: A(x) = 1 + x + 2*x^2 + 5*x^3 + 12*x^4 + 29*x^5 + 71*x^6 + 175*x^7 +...
%e where
%e A(x) = 1 + x/(1-x) + x^2/(1-x)^3 + x^3/(1-x)^4 + x^4/(1-x)^7 + x^5/(1-x)^6 + x^6/(1-x)^12 + x^7/(1-x)^8 + x^8/(1-x)^15 + x^9/(1-x)^13 + x^10/(1-x)^18 +...
%o (PARI) {a(n)=polcoeff(1+sum(m=1,n,x^m/(1-x+x*O(x^n))^sigma(m)),n)}
%o for(n=0,40,print1(a(n),", "))
%Y Cf. A227236, A000203.
%K nonn
%O 0,3
%A _Paul D. Hanna_, Jul 03 2013
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