OFFSET
0,3
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (0,0,0,1248,0,0,0,-1).
FORMULA
G.f.: -(x^2-x-1)*(x^4+25*x^2+1) / (x^8-1248*x^4+1). - Colin Barker, Dec 04 2013
a(n) = 1248*a(n-4) - a(n-8) for n>7. - Vincenzo Librandi, Jan 16 2014
MATHEMATICA
Denominator[Convergents[Sqrt[623], 30]] (* Harvey P. Dale, Jun 28 2012 *)
PROG
(Magma) I:=[1, 1, 24, 25, 1224, 1249, 29951, 31200]; [n le 8 select I[n] else 1248*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Jan 16 2014
CROSSREFS
KEYWORD
nonn,cofr,frac,easy,less
AUTHOR
EXTENSIONS
More terms from Colin Barker, Dec 04 2013
STATUS
approved