A047179 Number of nonempty subsets of {1,2,...,n} in which exactly 4/5 of the elements are <= (n-1)/2.

0, 0, 0, 0, 0, 0, 0, 0, 5, 6, 30, 35, 105, 120, 280, 315, 666, 745, 1665, 1881, 4785, 5490, 14850, 17160, 45331, 52339, 131859, 151775, 371735, 427336, 1048840, 1207765, 3021240, 3490050

Offset

1,9

Links

Table of n, a(n) for n=1..34.

Crossrefs

Sequence in context: A152118 A041056 A042643 * A166023 A137762 A177118

Adjacent sequences: A047176 A047177 A047178 * A047180 A047181 A047182

Keyword

nonn

Author

Clark Kimberling

Status

approved