OFFSET
0,3
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2,1,-2,-1).
FORMULA
MATHEMATICA
Table[LucasL[n, 1]*n, {n, 0, 36}] (* Zerinvary Lajos, Jul 09 2009 *)
CoefficientList[Series[x * (1 + 4*x - x^2)/(1 - x - x^2)^2, {x, 0, 40}], x] (* Vincenzo Librandi, Dec 13 2012 *)
LinearRecurrence[{2, 1, -2, -1}, {0, 1, 6, 12}, 40] (* Harvey P. Dale, Apr 03 2013 *)
PROG
(Magma) I:=[0, 1, 6, 12]; [n le 4 select I[n] else 2*Self(n-1) + Self(n-2) - 2*Self(n-3) - Self(n-4): n in [1..40]]; // Vincenzo Librandi, Dec 13 2012
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
R. J. Mathar, Oct 26 2008
STATUS
approved