A052869 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A052869

A simple grammar.

0, 1, 2, 4, 11, 29, 88, 271, 876, 2880, 9699, 33106, 114575, 400547, 1413333, 5025026, 17987892, 64769123, 234438337, 852519108, 3113091384, 11410682109, 41967420293, 154832147286, 572853387928, 2124996514900, 7901625442544, 29446874224295, 109965454516498

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

LINKS

Table of n, a(n) for n=0..28.

INRIA Algorithms Project, Encyclopedia of Combinatorial Structures 840

MAPLE

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

CROSSREFS

Sequence in context: A148143 A148144 A148145 * A316768 A052831 A339834

Adjacent sequences: A052866 A052867 A052868 * A052870 A052871 A052872

KEYWORD

easy,nonn

AUTHOR

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

EXTENSIONS

More terms from Sean A. Irvine, Dec 01 2021

STATUS

approved