A095669 Seventh column (m=6) of (1,4)-Pascal triangle A095666.

4, 25, 91, 252, 588, 1218, 2310, 4092, 6864, 11011, 17017, 25480, 37128, 52836, 73644, 100776, 135660, 179949, 235543, 304612, 389620, 493350, 618930, 769860, 950040, 1163799, 1415925, 1711696, 2056912, 2457928, 2921688, 3455760, 4068372

Offset: 0

Author

Wolfdieter Lang, Jun 11 2004

Keywords

• nonn
• easy

Comments

If Y is a 4-subset of an n-set X then, for n>=9, a(n-9) is the number of 6-subsets of X having at most one element in common with Y. - Milan Janjic, Dec 08 2007

Formula

G.f.: (4-3*x)/(1-x)^7.

a(n) = 4*b(n)-3*b(n-1) = (n+24)*binomial(n+5, 5)/6, with b(n):=binomial(n+6, 6)= A000579(n+6, 6).