A369784 Expansion of e.g.f. exp( (exp(2*(exp(x)-1))-1)/2 ).
1, 1, 4, 21, 137, 1068, 9663, 99249, 1137858, 14373531, 198031153, 2951536030, 47270242621, 808917666365, 14720125466652, 283667520561633, 5768057979319853, 123364873473674732, 2767400573883314755, 64950007415991458989, 1591227433994704322322
Offset: 0
Keywords
Programs
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PARI
my(N=30, x='x+O('x^N)); Vec(serlaplace(exp((exp(2*(exp(x)-1))-1)/2)))
Formula
a(n) = Sum_{k=0..n} Stirling2(n,k) * A004211(k).