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A048065 Number of nonempty subsets of {1,2,...,n} in which exactly 1/5 of the elements are <= (n-4)/2. 0
0, 0, 0, 0, 0, 5, 15, 30, 70, 105, 213, 286, 558, 720, 1500, 1935, 4455, 5775, 13895, 17876, 42484, 53859, 124761, 156065, 357825, 444015, 1028500, 1272155, 3002795, 3709043, 8871603, 10935267, 26243427 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,6

LINKS

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

CROSSREFS

Sequence in context: A194150 A246817 A010898 * A048021 A225325 A133268

Adjacent sequences:  A048062 A048063 A048064 * A048066 A048067 A048068

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified December 7 20:44 EST 2019. Contains 329849 sequences. (Running on oeis4.)