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, 126, 0, -1).
FORMULA
G.f.: (31 + 63*x + 31*x^2 - x^3)/(1 - 126*x^2 + x^4). - Vincenzo Librandi, Dec 09 2013
a(n) = 126*a(n-2) - a(n-4). - Vincenzo Librandi, Dec 09 2013
MATHEMATICA
Numerator[Convergents[Sqrt[992], 30]] (* or *) CoefficientList[Series[(31 + 63 x + 31 x^2 - x^3)/(1 - 126 x^2 + x^4), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 09 2013 *)
PROG
(Magma) I:=[31, 63, 3937, 7937]; [n le 4 select I[n] else 126*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Dec 09 2013
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Vincenzo Librandi, Dec 09 2013
STATUS
approved