OFFSET
1,1
COMMENTS
The identity (388962n^2+1764n+1)^2-(441n^2+2n)*(18522n+42)^2=1 can be written as A157741(n)^2-A158321(n)*a(n)^2=1 (see the second comment in A157741). - Vincenzo Librandi, Feb 05 2012
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..10000
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
G.f.: x*(18564-42*x)/(1-x)^2. - Vincenzo Librandi, Feb 05 2012
a(n) = 2*a(n-1)-a(n-2). - Vincenzo Librandi, Feb 05 2012
MAPLE
MATHEMATICA
LinearRecurrence[{2, -1}, {18564, 37086}, 50] (* Vincenzo Librandi, Feb 05 2012 *)
18522*Range[30]+42 (* Harvey P. Dale, Apr 02 2023 *)
PROG
(Magma) I:=[18564, 37086]; [n le 2 select I[n] else 2*Self(n-1)-Self(n-2): n in [1..50]]; // Vincenzo Librandi, Feb 05 2012
(PARI) for(n=1, 40, print1(18522n + 42", ")); \\ Vincenzo Librandi, Feb 05 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Mar 05 2009
STATUS
approved