A368447 Expansion of e.g.f. exp(-x) / (1 + log(1 - 3*x)).
1, 2, 22, 305, 5767, 136526, 3883258, 128933255, 4893787021, 208996349714, 9917947451590, 517743558041981, 29485295251306867, 1819129033610512958, 120867373194394631242, 8604378456170991789779, 653370570548903023444249, 52714379598185711313436226
Offset: 0
Keywords
Programs
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PARI
a_vector(n) = my(v=vector(n+1)); for(i=0, n, v[i+1]=(-1)^i+sum(j=1, i, 3^j*(j-1)!*binomial(i, j)*v[i-j+1])); v;
Formula
a(n) = (-1)^n + Sum_{k=1..n} 3^k * (k-1)! * binomial(n,k) * a(n-k).