A047184 - 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

A047184

Number of nonempty subsets of {1,2,...,n} in which exactly 2/3 of the elements are <= (n-2)/2.

0, 0, 0, 0, 0, 4, 5, 15, 18, 51, 63, 175, 220, 596, 759, 2037, 2625, 7000, 9108, 24156, 31683, 83667, 110487, 290719, 386155, 1012935, 1352263, 3537703, 4743700, 12381252, 16666715, 43411489, 58639599

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

OFFSET

1,6

LINKS

Table of n, a(n) for n=1..33.

CROSSREFS

Sequence in context: A369790 A330857 A066516 * A002509 A230983 A100234

Adjacent sequences: A047181 A047182 A047183 * A047185 A047186 A047187

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved