A096946 Ninth column of (1,5)-Pascal triangle A096940.

5, 41, 189, 645, 1815, 4455, 9867, 20163, 38610, 70070, 121550, 202878, 327522, 513570, 784890, 1172490, 1716099, 2465991, 3485075, 4851275, 6660225, 9028305, 12096045, 16031925, 21036600, 27347580, 35244396, 45054284, 57158420

Offset

0,1

Comments

If Y is a 5-subset of an n-set X then, for n>=12, a(n-12) is the number of 8-subsets of X having at most one element in common with Y. > - Milan Janjic, Dec 08 2007

Links

Table of n, a(n) for n=0..28.

Formula

a(n)= (n+40)*binomial(n+7, 7)/8 = 5*b(n)-4*b(n-1), with b(n):=A000581(n+8)=binomial(n+8, 8).

G.f.: (5-4*x)/(1-x)^9.

Crossrefs

Eighth column: A096945; tenth column: A096947.

Sequence in context: A270674 A271001 A258229 * A027954 A270623 A322420

Adjacent sequences: A096943 A096944 A096945 * A096947 A096948 A096949

Keyword

nonn,easy

Author

Wolfdieter Lang, Jul 16 2004

Status

approved