A048088 Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= (n+3)/3.

0, 0, 0, 0, 1, 3, 12, 30, 60, 121, 217, 385, 700, 1260, 2521, 4960, 9460, 20020, 38500, 71071, 148161, 276549, 503685, 1071525, 2006508, 3681588, 8013256, 14981556, 27412041, 60042147, 111406614, 202871284, 447617884, 828004144

Offset

1,6

Links

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

Crossrefs

Sequence in context: A057671 A027480 A135503 * A064181 A281434 A296289

Adjacent sequences: A048085 A048086 A048087 * A048089 A048090 A048091

Keyword

nonn

Author

Clark Kimberling

Status

approved