OFFSET
0,2
LINKS
FORMULA
a(n) = 2*n^2 + 11*n.
a(n) = a(n-1) + 4*n + 9 (with a(0)=0). - Vincenzo Librandi, Nov 24 2010
From Elmo R. Oliveira, Nov 29 2024: (Start)
G.f.: x*(13 - 9*x)/(1-x)^3.
E.g.f.: exp(x)*x*(13 + 2*x).
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n > 2. (End)
MATHEMATICA
s=0; lst={s}; Do[s+=n++ +13; AppendTo[lst, s], {n, 0, 7!, 4}]; lst (* Vladimir Joseph Stephan Orlovsky, Nov 19 2008 *)
Table[n(2n+11), {n, 0, 50}] (* or *) LinearRecurrence[{3, -3, 1}, {0, 13, 30}, 50] (* Harvey P. Dale, Mar 17 2019 *)
PROG
(PARI) a(n)=n*(2*n+11) \\ Charles R Greathouse IV, Jun 17 2017
CROSSREFS
KEYWORD
easy,nonn,changed
AUTHOR
Omar E. Pol, May 19 2008
STATUS
approved