A183229 G.f.: Sum_{n>=0} a(n)*x^n/n!^2 = Product_{n>=1} (1 + x^n/n!^2).
1, 1, 1, 10, 17, 126, 3862, 12741, 110609, 1929430, 167593826, 845443941, 11064102326, 178820437901, 7538334414717, 1483432379403435, 10962589471724049, 189591619730952006, 3827839859607324106
Offset: 0
Keywords
Examples
G.f.: A(x) = 1 + x + x^2/2!^2 + 10*x^3/3!^2 + 17*x^4/4!^2 +... A(x) = (1 + x)*(1 + x^2/2!^2)*(1 + x^3/3!^2)*(1 + x^4/4!^2)*...
Programs
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PARI
{a(n)=n!^2*polcoeff(prod(k=1, n, 1+x^k/k!^2 +x*O(x^n)), n)}