A052829 A simple grammar.

0, 1, 2, 4, 10, 25, 69, 197, 583, 1762, 5441, 17042, 54072, 173334, 560659, 1827306, 5995570, 19787135, 65643226, 218777532, 732181107, 2459576149, 8290442750, 28031056619, 95045477945, 323112137130, 1101073839413, 3760472582922, 12869488098939, 44127605854574

Offset

0,3

Links

Table of n, a(n) for n=0..29.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 794

Formula

G.f.: (x/(1-x))*Product_{k>=1} (1+x^k)^a(k). - Vladeta Jovovic, Jul 22 2004

G.f. A(x) satisfies: A(x) = (x/(1 - x)) * exp(Sum_{k>=1} (-1)^(k+1) * A(x^k) / k). - Ilya Gutkovskiy, Jun 28 2021

Maple

spec := [S, {B=Sequence(Z, 1 <= card), C=PowerSet(S), S=Prod(C, B)}, unlabeled]: seq(combstruct[count](spec, size=n), n=0..20);

Crossrefs

Cf. A052870 (first differences).

Sequence in context: A191768 A027432 A032128 * A339295 A001998 A005817

Adjacent sequences: A052826 A052827 A052828 * A052830 A052831 A052832

Keyword

easy,nonn

Author

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

Extensions

More terms from Alois P. Heinz, Mar 16 2016

Status

approved