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%I #5 Mar 30 2012 18:37:37
%S 1,1,3,17,153,1961,33267,709937,18375001,561358441,19825203355,
%T 796240555449,35891569819217,1796230428709665,98908294526888507,
%U 5946867742763879145,387872935717894524737,27288493956110862779089,2060691818131992283884307,166303287155431671466946881
%N G.f.: 1/(1-x) = Sum_{n>=0} a(n) * x^n * Product_{k=1..n} (1 - k*x)/(1 + k*x).
%e G.f.: 1/(1-x) = 1 + 1*x*(1-x)/(1+x) + 3*x^2*(1-x)*(1-2*x)/((1+x)*(1+2*x)) + 17*x^3*(1-x)*(1-2*x)*(1-3*x)/((1+x)*(1+2*x)*(1+3*x)) + 153*x^4*(1-x)*(1-2*x)*(1-3*x)*(1-4*x)/((1+x)*(1+2*x)*(1+3*x)*(1+4*x)) +...
%o (PARI) {a(n)=if(n==0, 1, 1-polcoeff(sum(k=0, n-1, a(k)*x^k*prod(j=1, k, (1-j*x)/(1+j*x+x*O(x^n)))), n))}
%o for(n=0,25,print1(a(n),", "))
%Y Cf. A208833.
%K nonn
%O 0,3
%A _Paul D. Hanna_, Mar 01 2012
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