cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A095665 Tenth column (m=9) of (1,3)-Pascal triangle A095660.

Original entry on oeis.org

3, 28, 145, 550, 1705, 4576, 11011, 24310, 50050, 97240, 179894, 319124, 545870, 904400, 1456730, 2288132, 3513917, 5287700, 7811375, 11347050, 16231215, 22891440, 31865925, 43826250, 59603700, 80219568, 106919868, 141214920
Offset: 0

Views

Author

Wolfdieter Lang, Jun 11 2004

Keywords

Comments

If Y is a 3-subset of an n-set X then, for n>=11, a(n-11) is the number of 9-subsets of X having at most one element in common with Y. - Milan Janjic, Nov 23 2007

Crossrefs

Ninth column: A095663.

Programs

  • Mathematica
    Table[Binomial[n+8,8] (n+27)/9,{n,0,30}] (* or *) LinearRecurrence[{10,-45,120,-210,252,-210,120,-45,10,-1},{3,28,145,550,1705,4576,11011,24310,50050,97240},30] (* Harvey P. Dale, Oct 13 2017 *)

Formula

a(n)= binomial(n+8, 8)*(n+27)/9 = 3*b(n)-2*b(n-1), with b(n):=binomial(n+9, 9); cf. A000582.
G.f.: (3-2*x)/(1-x)^10.