OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (0,0,0,1248,0,0,0,-1).
FORMULA
G.f.: (24 +25*x +599*x^2 +624*x^3 +599*x^4 -25*x^5 +24*x^6 -x^7)/(1 -1248*x^4 +x^8). - Vincenzo Librandi, Nov 18 2013
a(n) = 1248*a(n-4) - a(n-8). - Vincenzo Librandi, Nov 18 2013
MATHEMATICA
Numerator[Convergents[Sqrt[623], 30]] (* or *) CoefficientList[Series[(24 + 25 x + 599 x^2 + 624 x^3 + 599 x^4 - 25 x^5 + 24 x^6 - x^7)/(1 - 1248 x^4 + x^8), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 18 2013 *)
PROG
(Magma) I:=[24, 25, 599, 624, 30551, 31175, 747576, 778751]; [n le 8 select I[n] else 1248*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Nov 18 2013
CROSSREFS
KEYWORD
nonn,cofr,frac,easy,less
AUTHOR
STATUS
approved