OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (0, 122, 0, -1).
FORMULA
G.f.: (30 +61*x +30*x^2 -x^3)/(1 -122*x^2 +x^4), - Vincenzo Librandi, Dec 05 2013
a(n) = 122*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 05 2013
MATHEMATICA
Numerator[Convergents[Sqrt[930], 30]] (* Harvey P. Dale, Apr 27 2012 *)
CoefficientList[Series[(30 + 61 x + 30 x^2 - x^3)/(1 - 122 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 05 2013 *)
PROG
(Magma) I:=[30, 61, 3690, 7441]; [n le 4 select I[n] else 122*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 05 2013
CROSSREFS
KEYWORD
nonn,cofr,frac,easy
AUTHOR
EXTENSIONS
More terms from Vincenzo Librandi, Dec 05 2013
STATUS
approved