OFFSET
0,2
LINKS
Colin Barker, Table of n, a(n) for n = 0..500
Index entries for linear recurrences with constant coefficients, signature (47,-1).
FORMULA
a(n) = Fibonacci(4*n)*Lucas(4*n) = 21*A049668(n).
G.f.: 21*x / ( 1-47*x+x^2 ). - R. J. Mathar, Sep 30 2013
From Colin Barker, Apr 06 2017: (Start)
a(n) = (47 + 21*sqrt(5))^(1-n)*(-2^n+(2207 + 987*sqrt(5))^n) / (105 + 47*sqrt(5)).
a(n) = 47*a(n-1) - a(n-2) for n > 1.
(End)
MATHEMATICA
Fibonacci[8Range[0, 20]] (* Harvey P. Dale, Jun 22 2013 *)
PROG
(MuPAD) numlib::fibonacci(8*n) $ n = 0..25;
(Sage) [fibonacci(8*n) for n in range(0, 15)] # Zerinvary Lajos, May 15 2009
(Magma) [Fibonacci(8*n): n in [0..100]]; // Vincenzo Librandi, Apr 17 2011
(PARI) concat(0, Vec(21*x / (1 - 47*x + x^2) + O(x^30))) \\ Colin Barker, Apr 06 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Zerinvary Lajos, May 09 2008
STATUS
approved