A379661 Expansion of e.g.f. (1/x) * Series_Reversion( x * (exp(-2*x) - x) ).

1, 3, 32, 638, 18992, 757152, 37946944, 2294428880, 162614380544, 13224995258624, 1214230905887744, 124244350629669888, 14021254268885487616, 1730161184870597414912, 231756218205467830255616, 33492293939832097344370688, 5194237715163522538324557824, 860510764365813120075516739584

Offset

0,2

Links

Table of n, a(n) for n=0..17.

Formula

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

Prog

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

Crossrefs

Cf. A377890, A379662.

Sequence in context: A370462 A295385 A331799 * A129431 A373857 A297558

Adjacent sequences: A379658 A379659 A379660 * A379662 A379664 A379666

Keyword

nonn,new

Author

Seiichi Manyama, Dec 29 2024

Status

approved