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, 902, 0, -1).
FORMULA
a(0)=1, a(1)=15, a(2)=901, a(3)=13530, a(n)=902*a(n-2)-a(n-4). - Harvey P. Dale, Sep 25 2013
G.f.: -(x^2-15*x-1) / ((x^2-30*x-1)*(x^2+30*x-1)). - Colin Barker, Nov 19 2013
MATHEMATICA
Denominator[Convergents[Sqrt[904], 30]] (* or *) LinearRecurrence[ {0, 902, 0, -1}, {1, 15, 901, 13530}, 30] (* Harvey P. Dale, Sep 25 2013 *)
PROG
(Magma) I:=[1, 15, 901, 13530]; [n le 4 select I[n] else 902*Self(n-2)-Self(n-4): n in [1..30]]; // Vincenzo Librandi, Jan 28 2014
CROSSREFS
KEYWORD
nonn,frac,easy
AUTHOR
EXTENSIONS
Additional term from Colin Barker, Nov 19 2013
STATUS
approved