OFFSET
1,1
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Index entries for linear recurrences with constant coefficients, signature (3,-2).
FORMULA
G.f.: (8*x-5*x^2)/(1-3*x+2*x^2). [Philippe Deléham, Feb 09 2009]
a(n) = 3*a(n-1)-2*a(n-2) = 11*2^(n-1)-3. [R. J. Mathar, Feb 19 2009]
MATHEMATICA
LinearRecurrence[{3, -2}, {8, 19}, 30] (* Vincenzo Librandi, May 02 2012 *)
NestList[2#+3&, 8, 30] (* Harvey P. Dale, Oct 17 2016 *)
PROG
(Magma) I:=[8, 19]; [n le 2 select I[n] else 3*Self(n-1)-2*Self(n-2): n in [1..30]]; // _Librandi Vincenzo_, May 02 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Vincenzo Librandi, Feb 08 2009
STATUS
approved