A376039 E.g.f. satisfies A(x) = (-log(1 - x / (1 - A(x))^3)) * (1 - A(x)).
0, 1, 5, 65, 1376, 40454, 1523464, 69979734, 3794288280, 237186275520, 16794542216088, 1328558461234080, 116126748206895216, 11114654375545182864, 1156103394150386866560, 129855826037621953356864, 15664344145032570448561920, 2019701492029961287845196032
Offset: 0
Keywords
Programs
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PARI
a(n) = sum(k=1, n, (3*n-2)!/(3*n-k-1)!*abs(stirling(n, k, 1)));
Formula
a(n) = Sum_{k=1..n} (3*n-2)!/(3*n-k-1)! * |Stirling1(n,k)|.
E.g.f.: Series_Reversion( (1 - x)^3 * (1 - exp(-x / (1 - x))) ).