A376037 E.g.f. satisfies A(x) = (exp(x / (1 - A(x))^2) - 1) / (1 - A(x)).
0, 1, 7, 115, 3047, 111771, 5244555, 299941195, 20239069807, 1574068019851, 138641219870243, 13640672949173403, 1482772864485867399, 176478769995088245595, 22825571074271407363771, 3187825736999237502879019, 478120273969744650293424095
Offset: 0
Keywords
Programs
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PARI
a(n) = sum(k=1, n, (2*n+2*k-2)!/(2*n+k-1)!*stirling(n, k, 2));
Formula
a(n) = Sum_{k=1..n} (2*n+2*k-2)!/(2*n+k-1)! * Stirling2(n,k).
E.g.f.: Series_Reversion( (1 - x)^2 * log(1 + x * (1 - x)) ).