OFFSET
0,1
LINKS
Shawn A. Broyles, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
G.f.: (2-5x+7x^2-2x^3)/(1-x)^4. a(n)=2+n(1+2n^2+3n)/6 = 2+A000330(n). - R. J. Mathar, Jan 08 2009
MATHEMATICA
a=2; lst={}; Do[a=n^2+a; AppendTo[lst, a], {n, 0, 5!}]; lst
nxt[{n_, a_}]:={n+1, (n+1)^2+a}; NestList[nxt, {0, 2}, 50][[;; , 2]] (* or *) LinearRecurrence[{4, -6, 4, -1}, {2, 3, 7, 16}, 50] (* Harvey P. Dale, Sep 05 2023 *)
PROG
(PARI) a(n) = n*(n+1)*(2*n+1)/6 + 2; \\ Altug Alkan, Apr 30 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vladimir Joseph Stephan Orlovsky, Dec 17 2008
STATUS
approved