OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000 (first 100 terms from Matt C. Anderson)
Index entries for linear recurrences with constant coefficients, signature (1,5).
FORMULA
G.f.: (1+x)/(1-x-5*x^2).
a(n) = Sum_{k=0..n+1} A122950(n+1,k)*4^(n+1-k). - Philippe Deléham, Jan 08 2008
a(n) = ((21 - 3*sqrt(21))/42)*(1/2 - (1/2)*sqrt(21))^n + ((21 + 3*sqrt(21))/42)*(1/2 + (1/2)*sqrt(21))^n. - Richard Choulet, Nov 20 2008
MATHEMATICA
LinearRecurrence[{1, 5}, {1, 2}, 30] (* Harvey P. Dale, Jul 23 2013 *)
PROG
(PARI) x='x+O('x^99); Vec((1+x)/(1-x-5*x^2)) \\ Altug Alkan, Aug 28 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Philippe Deléham, Jan 03 2008
STATUS
approved