A048030 Number of nonempty subsets of {1,2,...,n} in which exactly 1/4 of the elements are <= (n-3)/3.

0, 0, 0, 0, 0, 10, 20, 35, 77, 140, 252, 505, 1000, 1936, 3652, 7305, 14313, 25805, 52325, 104651, 184736, 379676, 769556, 1334942, 2764139, 5654894, 9685364, 20191604, 41641244, 70639794, 148064400, 307271007, 517215283

Offset

1,6

Links

Table of n, a(n) for n=1..33.

Crossrefs

Sequence in context: A187712 A130720 A046285 * A048011 A188334 A266087

Adjacent sequences: A048027 A048028 A048029 * A048031 A048032 A048033

Keyword

nonn

Author

Clark Kimberling

Status

approved