OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (0,0,0,0,0,1298,0,0,0,0,0,-1).
FORMULA
G.f.: -(x^4 -2*x^3 +5*x^2 +2*x +1)*(x^6 -9*x^3 -1) / ((x^2 -3*x -1)*(x^2 +3*x -1)*(x^4 -3*x^3 +10*x^2 +3*x +1)*(x^4 +3*x^3 +10*x^2 -3*x +1)). - Colin Barker, Nov 16 2013
a(n) = 1298*a(n-6) - a(n-12) for n>11. - Vincenzo Librandi, Dec 17 2013
MATHEMATICA
Denominator[Convergents[Sqrt[208], 30]] (* Vincenzo Librandi, Dec 17 2013 *)
PROG
(Magma) I:=[1, 2, 5, 7, 19, 45, 1279, 2603, 6485, 9088, 24661, 58410]; [n le 12 select I[n] else 1298*Self(n-6)-Self(n-12): n in [1..40]]; // Vincenzo Librandi, Dec 17 2013
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 16 2013
STATUS
approved