A383165 Expansion of e.g.f. log(1 + (exp(2*x) - 1)/2)^2 / 2.
0, 0, 1, 3, 3, -10, -30, 112, 588, -2448, -18960, 87296, 911328, -4599296, -61152000, 335523840, 5464904448, -32363874304, -627708979200, 3987441516544, 90133968949248, -610866587369472, -15823700431503360, 113884455221854208, 3334995367266582528, -25385597162671308800
Offset: 0
Keywords
Programs
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PARI
a(n) = sum(k=2, n, 2^(n-k)*stirling(n, k, 2)*stirling(k, 2, 1));
Formula
a(n) = Sum{k=2..n} 2^(n-k) * Stirling2(n,k) * Stirling1(k,2).