OFFSET
1,2
COMMENTS
If a(n)=x and a(n+1)=y then (x^2+y^2)/(xy+1)=64.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..200
Index entries for linear recurrences with constant coefficients, signature (64,-1).
FORMULA
G.f.: 8*x^2/(1 -64*x +x^2). - R. J. Mathar, Jan 05 2011
MATHEMATICA
CoefficientList[Series[(8z)/(z^2-64z+1), {z, 0, 20}], z] (* Vincenzo Librandi, Jan 29 2012 *)
LinearRecurrence[{64, -1}, {0, 8}, 20] (* Harvey P. Dale, Dec 19 2023 *)
PROG
(Magma) I:=[0, 8]; [n le 2 select I[n] else 64*Self(n-1)-Self(n-2): n in [1..20]]; // Vincenzo Librandi, Jan 29 2012
(PARI) a(n)=([0, 1; -1, 64]^(n-1)*[0; 8])[1, 1] \\ Charles R Greathouse IV, Sep 01 2016
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Jan 04 2009
STATUS
approved