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, 450, 0, -1).
FORMULA
G.f.: (28 +225*x +28*x^2 -x^3)/(1 -450*x^2 +x^4). - Vincenzo Librandi, Nov 26 2013
a(n) = 450*a(n-2) - a(n-4). - Vincenzo Librandi, Nov 26 2013
MATHEMATICA
Numerator[Convergents[Sqrt[791], 30]] (* or *) CoefficientList[Series[(28 + 225 x + 28 x^2 - x^3)/(1 - 450 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 25 2013 *)
LinearRecurrence[{0, 450, 0, -1}, {28, 225, 12628, 101249}, 20] (* Harvey P. Dale, Jul 20 2024 *)
PROG
(Magma) I:=[28, 225, 12628, 101249]; [n le 4 select I[n] else 450*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Nov 26 2013
CROSSREFS
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved