OFFSET
0,2
FORMULA
a(n) = ((1+sqrt(5))*(7+sqrt(5))^n+(1-sqrt(5))*(7-sqrt(5))^n)/2.
G.f.: (1-2*x)/(1-14*x+44*x^2).
PROG
(MAGMA) [ n le 2 select 11*n-10 else 14*Self(n-1)-44*Self(n-2): n in [1..19] ];
CROSSREFS
KEYWORD
nonn
AUTHOR
Klaus Brockhaus, Jul 21 2009
STATUS
approved