A062989 a(n) = C(n+6, 6) - n - 1.

0, 5, 25, 80, 205, 456, 917, 1708, 2994, 4995, 7997, 12364, 18551, 27118, 38745, 54248, 74596, 100929, 134577, 177080, 230209, 295988, 376717, 474996, 593750, 736255, 906165, 1107540, 1344875, 1623130, 1947761, 2324752, 2760648, 3262589, 3838345, 4496352

Offset

0,2

Comments

In the Frey-Sellers reference this sequence is called {(n+2) over 6}_{4}, n >= 0.

Links

Harry J. Smith, Table of n, a(n) for n = 0..1000

D. D. Frey and J. A. Sellers, Generalizing Bailey's generalization of the Catalan numbers, The Fibonacci Quarterly, 39 (2001) 142-148.

Index entries for linear recurrences with constant coefficients, signature (7, -21, 35, -35, 21, -7, 1).

Formula

a(n) = A062985(n+2, 6) = (n+1)*(n+2)*(n^4 + 24*n^3 + 221*n^2 + 954*n + 1800)/6!.

G.f.: N(5;1, x)/(1-x)^7 with N(5;1, x)= 5-10*x+10*x^2-5*x^3+x^4 = (1-(1-x)^5)/x polynomial of second row of A062986.

a(0)=0, a(1)=5, a(2)=25, a(3)=80, a(4)=205, a(5)=456, a(6)=917, a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7). - Harvey P. Dale, Aug 08 2013

Mathematica

Table[Binomial[n+6, 6]-n-1, {n, 0, 40}] (* OR *) LinearRecurrence[ {7, -21, 35, -35, 21, -7, 1}, {0, 5, 25, 80, 205, 456, 917}, 40] (* Harvey P. Dale, Aug 08 2013 *)

Prog

(PARI) { for (n=0, 1000, write("b062989.txt", n, " ", binomial(n + 6, 6) - n - 1) ) } \\ Harry J. Smith, Aug 15 2009

Crossrefs

Seventh column (r=6) of FS(5) staircase array A062985.

Partial sums of A062988.

Sequence in context: A366158 A243303 A238449 * A122679 A264132 A355949

Adjacent sequences: A062986 A062987 A062988 * A062990 A062991 A062992

Keyword

nonn,easy

Author

Wolfdieter Lang, Jul 12 2001

Extensions

Simpler definition from Zerinvary Lajos, May 08 2006

Status

approved