A052781 G.f. A(x) satisfies: A(x) = exp( Sum_{k>=1} A(x^k)^5 * x^k / k ).

1, 1, 6, 46, 421, 4191, 44322, 487662, 5527722, 64091887, 756590138, 9062397539, 109866112785, 1345528776005, 16622049264020, 206882949204038, 2591780764974800, 32656149762325321, 413563728245999232, 5261307475883227222, 67207527369932430625

Offset

0,3

Comments

Appears to be the Euler transform of A052788. - Falk Hüffner, Dec 03 2015

Old name was: A simple grammar.

Links

Table of n, a(n) for n=0..20.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 738

Formula

G.f. A(x) satisfies: A(x) = exp( Sum_{k>=1} A(x^k)^5 * x^k / k ). - Ilya Gutkovskiy, May 26 2023

Maple

spec := [S, {B=Prod(Z, S, S, S, S, S), S=Set(B)}, unlabeled]: seq(combstruct[count](spec, size=n), n=0..20);

Crossrefs

Cf. A005750, A052751, A052773.

Cf. A052788.

Sequence in context: A349332 A365185 A111531 * A284109 A049378 A365056

Adjacent sequences: A052778 A052779 A052780 * A052782 A052783 A052784

Keyword

easy,nonn

Author

encyclopedia(AT)pommard.inria.fr, Jan 25 2000

Extensions

New name from Ilya Gutkovskiy, May 26 2023

Status

approved