A048044 Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= (n+1)/3.

0, 0, 0, 0, 1, 4, 10, 30, 60, 105, 217, 364, 588, 1260, 2250, 3960, 9460, 17380, 30745, 71071, 126763, 219765, 503685, 898380, 1572228, 3681588, 6619596, 11666760, 27412041, 49146654, 86461704, 202871284, 363087604, 639438019

Offset

1,6

Links

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

Crossrefs

Sequence in context: A151874 A344203 A330529 * A047188 A002220 A222807

Adjacent sequences: A048041 A048042 A048043 * A048045 A048046 A048047

Keyword

nonn

Author

Clark Kimberling

Status

approved