OFFSET
0,1
FORMULA
G(x) = 2*(1-x)/(1-6x-2x^2);
E(x) = (exp((1+sqrt(7))x) + exp((1-sqrt(7))x));
G.f.: G(0), where G(k)= 1 + 1/(1 - x*(7*k-1)/(x*(7*k+6) - 1/G(k+1))); (continued fraction). - Sergei N. Gladkovskii, Jun 03 2013
PROG
(Sage) [lucas_number2(n, 2, -6) for n in range(0, 23)] # Zerinvary Lajos, Apr 30 2009
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Miklos Kristof, Mar 26 2007
STATUS
approved