OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..170
Index entries for linear recurrences with constant coefficients, signature (7,-14,8).
FORMULA
a(n) = 6*(4^n - 2^n) + 1. - Ralf Stephan, Apr 06 2004
G.f.: (-1 - 6*x + 4*x^2)/((x-1)*(2*x-1)*(4*x-1)). - R. J. Mathar, Jun 11 2013
From Elmo R. Oliveira, Sep 12 2024: (Start)
E.g.f.: exp(x)*(6*exp(x)*(exp(2*x) - 1) + 1).
a(n) = 7*a(n-1) - 14*a(n-2) + 8*a(n-3) for n > 2. (End)
MAPLE
seq(6*bernoulli(2, 2^i), i=0..24);
MATHEMATICA
6*BernoulliB[2, 2^Range[0, 30]] (* Paolo Xausa, Sep 16 2024 *)
PROG
(Magma) [6 * (4^n - 2^n) + 1: n in [0..40]]; // Vincenzo Librandi, Apr 25 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved