A048080 Number of nonempty subsets of {1,2,...,n} in which exactly 1/6 of the elements are <= (n+2)/3.

0, 0, 0, 0, 0, 0, 0, 3, 18, 24, 84, 224, 280, 630, 1270, 1527, 2937, 5742, 6930, 15015, 35035, 44044, 108164, 260064, 328944, 767244, 1720944, 2152710, 4738410, 10329750, 12890614, 28583709, 64071194, 80628669, 184657869

Offset

1,8

Links

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

Crossrefs

Sequence in context: A131860 A346421 A263578 * A306279 A169598 A202359

Adjacent sequences: A048077 A048078 A048079 * A048081 A048082 A048083

Keyword

nonn

Author

Clark Kimberling

Status

approved