OFFSET
0,2
COMMENTS
REFERENCES
L. Comtet, Advanced Combinatorics, Reidel, 1974, p. 199, #3.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..300
Index entries for linear recurrences with constant coefficients, signature (12,-47,72,-36).
FORMULA
G.f.: -2*x*(6*x^2-1) / ((x-1)*(2*x-1)*(3*x-1)*(6*x-1)). - Colin Barker, Dec 06 2012
a(n-1) = (limit of (Sum_{k>=0} (1/(6*k + 1)^s - 1/(6*k + 2)^s - 2/(6*k + 3)^s - 1/(6*k + 4)^s + 1/(6*k + 5)^s + 2/(6*k + 6)^s) as s -> n))/zeta(n)*6^(n - 1). - Mats Granvik, Nov 14 2013
a(n) = 2*A160869(n). - R. J. Mathar, Nov 23 2018
MAPLE
MATHEMATICA
Table[(2^n-1)*(3^n-1), {n, 0, 5!}] (* Vladimir Joseph Stephan Orlovsky, Apr 28 2010 *)
PROG
(Magma) [(2^n-1)*(3^n-1): n in [0..30]]; // Vincenzo Librandi, Jun 05 2011
(PARI) for(n=0, 30, print1((2^n-1)*(3^n-1), ", ")) \\ G. C. Greubel, Jan 29 2018
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jan 29 2001
STATUS
approved