A379687 Expansion of e.g.f. (1/x) * Series_Reversion( x * exp(x) * (1 - 2*x*exp(x)) ).

1, 1, 11, 158, 3597, 107994, 4082695, 186003166, 9930511577, 608225910290, 42049314628251, 3239451955702038, 275220868466701861, 25565354021529630970, 2577774089234276245391, 280406846696018760511694, 32732658189778781519050161, 4081497882738710247779141922

Offset: 0

Author

Seiichi Manyama, Dec 29 2024

Keywords

• nonn

Crossrefs

Cf. A379659, A379688.

Programs

PARI

a(n) = sum(k=0, n, 2^(n-k)*(-k-1)^k*(2*n-k)!/(k!*(n-k)!))/(n+1);

Formula

a(n) = (1/(n+1)) * Sum_{k=0..n} 2^(n-k) * (-k-1)^k * (2*n-k)!/(k! * (n-k)!).