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, 160, 0, 0, 0, -1).
FORMULA
G.f.: (26 +27*x +53*x^2 +80*x^3 +53*x^4 -27*x^5 +26*x^6 -x^7)/(1 -160*x^4 +x^8). - Vincenzo Librandi, Nov 22 2013
a(n) = 160*a(n-4) - a(n-8). - Vincenzo Librandi, Nov 22 2013
MATHEMATICA
Numerator[Convergents[Sqrt[711], 30]] (* or *) CoefficientList[Series[(26 + 27 x + 53 x^2 + 80 x^3 + 53 x^4 - 27 x^5 + 26 x^6 - x^7)/(1 - 160 x^4 + x^8), {x, 0, 30}], x] (* Vincenzo Librandi, Nov 22 2013 *)
PROG
(Magma) I:=[26, 27, 53, 80, 4213, 4293, 8506, 12799]; [n le 8 select I[n] else 160*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Nov 22 2013
CROSSREFS
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved