OFFSET
0,2
COMMENTS
2*a(n)/2^n is the 2nd binomial transform of Fib(n-3).
LINKS
FORMULA
G.f.: (1-7x)/(1-10x+20x^2); a(n)=(1/2-sqrt(5)/5)(5+sqrt(5))^n+(1/2+sqrt(5)/5)(5-sqrt(5))^n.
MATHEMATICA
CoefficientList[Series[(1-7x)/(1-10x+20x^2), {x, 0, 20}], x] (* Harvey P. Dale, Mar 24 2011 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Mar 23 2004
STATUS
approved