OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,-6,4,-1).
FORMULA
(15 n + 1) (n + 2) (n + 1)/2.
G.f.: (1+44*x)/(1-x)^4. [Colin Barker, Apr 30 2012]
a(n) = 4*a(n-1) -6*a(n-2) +4*a(n-3) -a(n-4). - Vincenzo Librandi, Jun 29 2012
MATHEMATICA
CoefficientList[Series[(1+44*x)/(1-x)^4, {x, 0, 40}], x] (* Vincenzo Librandi, Jun 29 2012 *)
PROG
(Magma) I:=[1, 48, 186, 460]; [n le 4 select I[n] else 4*Self(n-1)-6*Self(n-2)+4*Self(n-3)-Self(n-4): n in [1..40]]; // Vincenzo Librandi, Jun 29 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Oct 06 2007, based on a suggestion from an unknown correspondent in 2004.
STATUS
approved