A371120 E.g.f. satisfies A(x) = 1 + x*A(x)^3*(exp(x*A(x)) - 1).
1, 0, 2, 3, 100, 545, 17946, 203497, 7194440, 132963777, 5172409630, 135827977241, 5868623306844, 200952952956769, 9665278822378466, 407661518051710665, 21789972653746494736, 1088515671895571005313, 64406426353877958253254
Offset: 0
Keywords
Programs
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PARI
a(n) = n!*sum(k=0, n\2, (n+2*k)!*stirling(n-k, k, 2)/((n-k)!*(n+k+1)!));
Formula
a(n) = n! * Sum_{k=0..floor(n/2)} (n+2*k)! * Stirling2(n-k,k)/( (n-k)! * (n+k+1)! ).