OFFSET
1,1
LINKS
T. D. Noe, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).
FORMULA
a(n) = T(n,3); T(n,k) = Sum_{i=1..n} binomial(n+1,i)*binomial(k-1,i-1)*binomial(n-i+k,k).
G.f.: 2*x*(1+2*x+4*x^2+2*x^3+x^4)/(1-x)^7. - Colin Barker, Mar 17 2012
a(n) = n*(n+1)*(n^4 +2*n^3 +11*n^2 +10*n +12)/36. - Bruno Berselli, Mar 17 2012
E.g.f.: (x/36)*(72 + 252*x + 264*x^2 + 108*x^3 + 18*x^4 + x^5)*exp(x). - G. C. Greubel, Jan 23 2022
MAPLE
A157052:=n->n*(n + 1)*(n^4 + 2*n^3 + 11*n^2 + 10*n + 12)/36; seq(A157052(n), n=1..50); # Wesley Ivan Hurt, Feb 03 2014
MATHEMATICA
Table[n(n+1)(n^4 +2n^3 +11n^2 +10n +12)/36, {n, 50}] (* Wesley Ivan Hurt, Feb 03 2014 *)
PROG
(Sage) [n*(n+1)*(n^4 +2*n^3 +11*n^2 +10*n +12)/36 for n in (1..50)] # G. C. Greubel, Jan 23 2022
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
R. H. Hardin, Feb 22 2009
STATUS
approved