A048022 Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= (n-2)/3.

0, 0, 0, 0, 0, 0, 0, 20, 35, 56, 168, 252, 360, 930, 1452, 2244, 6820, 11440, 18655, 52507, 86905, 139960, 372120, 617610, 1007216, 2702252, 4563344, 7573970, 20167170, 34220634, 57059772, 149465844, 254222289, 425926604

Offset

1,8

Links

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

Crossrefs

Sequence in context: A328051 A081962 A024755 * A255349 A254363 A229356

Adjacent sequences: A048019 A048020 A048021 * A048023 A048024 A048025

Keyword

nonn

Author

Clark Kimberling

Status

approved