OFFSET
1,1
COMMENTS
Positive values of x (or y) satisfying x^2 - 22xy + y^2 + 180 = 0. - Colin Barker, Feb 19 2014
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..200
Index entries for linear recurrences with constant coefficients, signature (22,-1).
FORMULA
a(n+2) = 22*a(n+1)-a(n).
a(n+1) = 11*a(n)+2*(30*a(n)^2-45)^0.5.
G.f.: -3*x*(-1+x)/(1-22*x+x^2). - R. J. Mathar, Nov 14 2007
a(n) = 3*A157014(n). - Colin Barker, Feb 19 2014
MATHEMATICA
CoefficientList[Series[3 (1 - x)/(1 - 22 x + x^2), {x, 0, 40}], x] (* Vincenzo Librandi, Feb 21 2014 *)
PROG
(Magma) I:=[3, 63]; [n le 2 select I[n] else 22*Self(n-1)-Self(n-2): n in [1..20]]; // Vincenzo Librandi, Feb 21 2014
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Richard Choulet, Oct 16 2007
EXTENSIONS
More terms from Paolo P. Lava, Aug 06 2008
STATUS
approved