A385066 E.g.f. A(x) satisfies A(x) = exp(x + x^3*A''(x)).
1, 1, 1, 7, 193, 12481, 1570201, 340513321, 117098181313, 60060238918849, 43839052690362481, 43879747204367814961, 58445034533293136385361, 101048138430710700967252945, 222098609829790469135187472009, 609650270727758340550662998605801, 2058153076335502227178904191401488641
Offset: 0
Keywords
Programs
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PARI
a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=v[i]+sum(j=0, i-1, (1+j)*sum(k=1, 2, stirling(2, k, 1)*j^k)*binomial(i-1, j)*v[j+1]*v[i-j])); v;
Formula
a(0) = 1; a(n) = a(n-1) + Sum_{k=0..n-1} (-k + k^3) * binomial(n-1,k) * a(k) * a(n-1-k).