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
G.f.: 6*x*(1 + 4*x + x^2)/(1 - x)^4.
a(n) = 4*a(n-1) - 6*a(n-2) + 4*a(n-3) - a(n-4) for n>3.
MATHEMATICA
Table[6 n^3, {n, 0, 40}] (* or *) CoefficientList[Series[6 x (1 + 4 x + x^2)/(1 - x)^4, {x, 0, 40}], x]
PROG
(Magma) [6*n^3: n in [0..40]] /* or */ I:=[0, 6, 48, 162]; [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]];
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jul 05 2014
STATUS
approved