OFFSET
0,4
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..300
Index entries for linear recurrences with constant coefficients, signature (0,10,0,-9).
FORMULA
a(n) = (3^n - 1)/(2^(3 - 2*Mod[n, 2])).
a(n) = 10*a(n-2) - 9*a(n-4). - Colin Barker, Jun 17 2015
G.f.: x*(3*x^2+x+1) / ((x-1)*(x+1)*(3*x-1)*(3*x+1)). - Colin Barker, Jun 17 2015
MATHEMATICA
Clear[a, n];
a[n_] := (3^n - 1)/(2^(3 - 2*Mod[n, 2]));
Table[a[n], {n, 0, 30}]
PROG
(PARI) concat(0, Vec(x*(3*x^2+x+1)/((x-1)*(x+1)*(3*x-1)*(3*x+1)) + O(x^100))) \\ Colin Barker, Jun 17 2015
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Roger L. Bagula, Dec 02 2008
EXTENSIONS
Edited by N. J. A. Sloane, Aug 15 2013
STATUS
approved