0,2

If X is an n-set and Y a fixed 7-subset of X then a(n-7) is equal to the number of 7-subsets of X intersecting Y. - Milan R. Janjic (agnus(AT)blic.net), Jul 30 2007

Index entries for two-way infinite sequences

Milan Janjic, Two Enumerative Functions

Expansion of (1-x^7)/(1-x)^8.

G.f.: (1-x^7)/(1-x)^8. a(-1-n)=a(n).

(PARI) a(n)=binomial(n+7, 7)-binomial(n, 7)

Sequence in context: A092365 A014343 A051192 this_sequence A008490 A023033 A000580

Adjacent sequences: A008497 A008498 A008499 this_sequence A008501 A008502 A008503

nonn

N. J. A. Sloane (njas(AT)research.att.com).