OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (3,-3,1).
FORMULA
a(n) = 30*n + a(n-1) - 24 for n>0, a(0)=0. - Vincenzo Librandi, Aug 03 2010
From G. C. Greubel, Aug 28 2016: (Start)
a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3).
G.f.: 6*x*(1 + 4*x)/(1 - x)^3.
E.g.f.: 3*x*(2 + 5*x)*exp(x). (End)
MATHEMATICA
s=0; lst={s}; Do[s+=n; AppendTo[lst, s], {n, 6, 8!, 30}]; lst (* Vladimir Joseph Stephan Orlovsky, Apr 03 2009 *)
Table[ 3*n*(5*n-3), {n, 0, 25}] (* or *) LinearRecurrence[{3, -3, 1}, {0, 6, 42}, 25] (* G. C. Greubel, Aug 28 2016 *)
PROG
(PARI) a(n) = 3*n*(5*n-3); \\ Michel Marcus, Aug 28 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, Jan 02 2009
STATUS
approved