OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (0,218,0,-1).
FORMULA
G.f.: -(x^2-6*x-1) / (x^4-218*x^2+1). - Colin Barker, Nov 20 2013
a(n) = 218*a(n-2) - a(n-4) for n>3. - Vincenzo Librandi, Dec 22 2013
MATHEMATICA
Denominator[Convergents[Sqrt[330], 30]] (* Vincenzo Librandi, Dec 22 2013 *)
LinearRecurrence[{0, 218, 0, -1}, {1, 6, 217, 1308}, 20] (* Harvey P. Dale, Sep 23 2018 *)
PROG
(Magma) I:=[1, 6, 217, 1308]; [n le 4 select I[n] else 218*Self(n-2)-Self(n-4): n in [1..40]]; // Vincenzo Librandi, Dec 22 2013
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 20 2013
STATUS
approved