OFFSET
1,1
COMMENTS
The identity (2048*n^2+128*n+1)^2-(16*n^2+n)*(512*n+16)^2=1 can be written as A157476(n)^2-A157474(n)*a(n)^2=1 (see also second comment in A157476). [rewritten by Bruno Berselli, Aug 22 2011]
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..10000
Vincenzo Librandi, X^2-AY^2=1
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
G.f.: 16*x*(33-x)/(1-x)^2. - Bruno Berselli, Aug 22 2011
a(1)=528, a(2)=1040, a(n) = 2*a(n-1)-a(n-2). - Harvey P. Dale, Dec 07 2011
MATHEMATICA
512*Range[40]+16 (* or *) LinearRecurrence[{2, -1}, {528, 1040}, 40] (* Harvey P. Dale, Dec 07 2011 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Mar 01 2009
STATUS
approved