A048077 Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= (n+2)/3.

0, 0, 0, 0, 1, 4, 12, 30, 60, 121, 217, 364, 700, 1260, 2250, 4960, 9460, 17380, 38500, 71071, 126763, 276549, 503685, 898380, 2006508, 3681588, 6619596, 14981556, 27412041, 49146654, 111406614, 202871284, 363087604, 828004144

Offset

1,6

Links

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

Crossrefs

Sequence in context: A099407 A011938 A047177 * A350424 A220264 A367097

Adjacent sequences: A048074 A048075 A048076 * A048078 A048079 A048080

Keyword

nonn

Author

Clark Kimberling

Status

approved