OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (0,1252,0,-1).
FORMULA
G.f.: -(x^2 - 25*x - 1) / (x^4 - 1252*x^2 + 1). - Colin Barker, Dec 04 2013
a(n) = 1252*a(n-2) - a(n-4) for n > 3. - Vincenzo Librandi, Jan 16 2014
MATHEMATICA
Denominator[Convergents[Sqrt[627], 30]] (* Vincenzo Librandi, Jan 16 2014 *)
PROG
(Magma) I:=[1, 25, 1251, 31300]; [n le 4 select I[n] else 1252*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Jan 16 2014
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Dec 04 2013
STATUS
approved