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

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