OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (0,602,0,-1).
FORMULA
G.f.: (30 +301*x +30*x^2 -x^3)/(1 -602*x^2 +x^4). - Vincenzo Librandi, Dec 03 2013
a(n) = 602*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 03 2013
MATHEMATICA
Numerator[Convergents[Sqrt[906], 30]] (* or *) CoefficientList[Series[(30 + 301 x + 30 x^2 - x^3)/(1 - 602 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 03 2013 *)
LinearRecurrence[{0, 602, 0, -1}, {30, 301, 18090, 181201}, 20] (* Harvey P. Dale, Jun 11 2017 *)
PROG
(Magma) I:=[30, 301, 18090, 181201]; [n le 4 select I[n] else 602*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 03 2013
CROSSREFS
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved