OFFSET
0,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (0,0,0,222,0,0,0,-1).
FORMULA
G.f.: (27 +28*x +83*x^2 +111*x^3 +83*x^4 -28*x^5 +27*x^6 -x^7)/(1 -222*x^4 +x^8). - Vincenzo Librandi, Nov 26 2013
a(n) = 222*a(n-4) - a(n-8). - Vincenzo Librandi, Nov 26 2013
MATHEMATICA
Numerator[Convergents[Sqrt[770], 30]] (* or *) CoefficientList[Series[(27 + 28 x + 83 x^2 + 111 x^3 + 83 x^4 - 28 x^5 + 27 x^6 - x^7)/(1 - 222 x^4 + x^8), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 25 2013 *)
PROG
(Magma) I:=[27, 28, 83, 111, 6077, 6188, 18453, 24641]; [n le 8 select I[n] else 222*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Nov 26 2013
CROSSREFS
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved