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, 238, 0, 0, 0, -1).
FORMULA
G.f.: (29 +30*x +89*x^2 +119*x^3 +89*x^4 -30*x^5 +29*x^6 -x^7)/(1 -238*x^4 +x^8). - Vincenzo Librandi, Dec 02 2013
a(n) = 238*a(n-4) - a(n-8). - Vincenzo Librandi, Dec 02 2013
MATHEMATICA
Numerator[Convergents[Sqrt[885], 30]] (* or *) CoefficientList[Series[(29 + 30 x + 89 x^2 + 119 x^3 + 89 x^4 - 30 x^5 + 29 x^6 - x^7)/(1 - 238 x^4 + x^8), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 02 2013 *)
LinearRecurrence[{0, 0, 0, 238, 0, 0, 0, -1}, {29, 30, 89, 119, 6991, 7110, 21211, 28321}, 30] (* Harvey P. Dale, May 15 2018 *)
PROG
(Magma) I:=[29, 30, 89, 119, 6991, 7110, 21211, 28321]; [n le 8 select I[n] else 238*Self(n-4)-Self(n-8): n in [1..30]]; // Vincenzo Librandi, Dec 02 2013
CROSSREFS
KEYWORD
nonn,cofr,frac,easy
AUTHOR
STATUS
approved