A377633 E.g.f. satisfies A(x) = (1 + x * A(x)^2 * exp(x*A(x)^2))^2.

1, 2, 22, 474, 15512, 685450, 38251212, 2582466950, 204744089104, 18650699228754, 1919767092675860, 220378941471652942, 27916112634179586456, 3868191824049865945178, 582034397153512353488284, 94509039130326185624148150, 16472375319790734221438146592, 3067435511995844132675459958178

Offset

0,2

Links

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

Formula

E.g.f.: B(x)^2, where B(x) is the e.g.f. of A364989.

a(n) = (n!/(2*n+1)) * Sum_{k=0..n} k^(n-k) * binomial(4*n+2,k)/(n-k)!.

Prog

(PARI) a(n) = n!*sum(k=0, n, k^(n-k)*binomial(4*n+2, k)/(n-k)!)/(2*n+1);

Crossrefs

Cf. A364989, A377630.

Sequence in context: A354943 A084949 A276454 * A137076 A090730 A090313

Adjacent sequences: A377630 A377631 A377632 * A377634 A377635 A377636

Keyword

nonn

Author

Seiichi Manyama, Nov 02 2024

Status

approved