A048087 Number of nonempty subsets of {1,2,...,n} in which exactly 1/5 of the elements are <= (n+3)/3.

0, 0, 0, 0, 0, 0, 3, 15, 20, 60, 140, 175, 360, 720, 891, 1935, 4455, 5775, 13895, 32487, 42484, 97188, 216580, 282165, 632706, 1418514, 1863880, 4259520, 9690000, 12833436, 29366007, 66481107, 88256147, 200571107, 452679491

Offset

1,7

Links

Table of n, a(n) for n=1..35.

Crossrefs

Sequence in context: A083545 A224872 A097571 * A316751 A001897 A074214

Adjacent sequences: A048084 A048085 A048086 * A048088 A048089 A048090

Keyword

nonn

Author

Clark Kimberling

Status

approved