A047189 Number of nonempty subsets of {1,2,...,n} in which exactly 3/5 of the elements are <= (n-2)/2.

0, 0, 0, 0, 0, 0, 0, 10, 15, 60, 84, 210, 280, 630, 846, 2142, 3045, 8400, 12320, 32802, 48048, 121110, 176670, 437580, 642642, 1608607, 2391895, 6034600, 9050470, 22712326, 34185606, 84996158, 128251383, 317302008

Offset

1,8

Links

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

Crossrefs

Sequence in context: A272307 A092192 A119039 * A278921 A035407 A020139

Adjacent sequences: A047186 A047187 A047188 * A047190 A047191 A047192

Keyword

nonn

Author

Clark Kimberling

Status

approved