OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..300
Index entries for linear recurrences with constant coefficients, signature (7,8).
FORMULA
G.f.: 6*x/(1-7*x-8*x^2). a(n+1) = 7*a(n)+8*a(n-1) for n>=1, a(0)=0, a(1)=6. - Philippe Deléham, Nov 19 2007
a(n) = 2*A132805(n). - R. J. Mathar, Jun 07 2011
From Oboifeng Dira, Jun 05 2020: (Start)
a(n) = 6*A015565(n).
a(n) = Sum_{k=0..n} binomial(3*n+1,3*k+2). (End)
MAPLE
MATHEMATICA
LinearRecurrence[{7, 8}, {0, 6}, 30] (* Harvey P. Dale, Mar 29 2018 *)
PROG
(Magma) [-(2/3)*(-1)^n+(2/3)*8^n: n in [0..25]]; // Vincenzo Librandi, Jun 08 2011
(PARI) a(n)=2*(8^n-(-1)^n)/3 \\ Charles R Greathouse IV, Jun 08 2011
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Paul Curtz, Nov 18 2007
STATUS
approved