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A048066 Number of nonempty subsets of {1,2,...,n} in which exactly 2/5 of the elements are <= (n-4)/2. 0
0, 0, 0, 0, 0, 0, 0, 20, 35, 105, 168, 364, 588, 1260, 2250, 4960, 9460, 20020, 38500, 77001, 148161, 286689, 560469, 1071525, 2143051, 4064071, 8259196, 15473436, 31705476, 58620692, 120894085, 221227279, 459855214 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,8

LINKS

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

CROSSREFS

Sequence in context: A255349 A254363 A229356 * A287055 A326403 A335251

Adjacent sequences:  A048063 A048064 A048065 * A048067 A048068 A048069

KEYWORD

nonn

AUTHOR

Clark Kimberling

STATUS

approved

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Last modified September 27 18:13 EDT 2020. Contains 337386 sequences. (Running on oeis4.)