OFFSET
0,1
REFERENCES
Shalosh B. Ekhad, N. J. A. Sloane and Doron Zeilberger, Automated Proof (or Disproof) of Linear Recurrences Satisfied by Pisot Sequences, Preprint, 2016.
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (2,0,-1).
FORMULA
a(n) = Fib(n+4)+1 = A000045(n+4)+1.
a(n) = 2a(n-1) - a(n-3).
G.f.: (4-2*x-3*x^2)/(1-x)/(1-x-x^2). - Colin Barker, Feb 21 2012
MATHEMATICA
CoefficientList[Series[(4-2*x-3*x^2)/(1-x)/(1-x-x^2), {x, 0, 40}], x](* Vincenzo Librandi, Apr 20 2012 *)
PROG
(Magma) I:=[4, 6, 9]; [n le 3 select I[n] else 2*Self(n-1)-Self(n-3): n in [1..40]]; // Vincenzo Librandi, Apr 20 2012
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved