OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (0,86,0,-1).
FORMULA
G.f.: -(x^2 -2*x -1) / (x^4 -86*x^2 +1). - Colin Barker, Nov 26 2013
a(n) = 86*a(n-2) - a(n-4) for n>3. - Vincenzo Librandi, Dec 26 2013
MATHEMATICA
Denominator[Convergents[Sqrt[462], 30]] (* Harvey P. Dale, Sep 30 2011 *)
CoefficientList[Series[(1 + 2 x - x^2)/(x^4 - 86 x^2 + 1), {x, 0, 30}], x] (* Vincenzo Librandi, Dec 26 2013 *)
PROG
(Magma) I:=[1, 2, 85, 172]; [n le 4 select I[n] else 86*Self(n-2)-Self(n-4): n in [1..40]]; // Vincenzo Librandi, Dec 26 2013
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
More terms from Colin Barker, Nov 26 2013
STATUS
approved