OFFSET
0,4
LINKS
FORMULA
G.f. : (1+x)/(1-2x+x^2-5x^3); a(n)=2a(n-1)-a(n-2)+5a(n-3); a(n)=sum{k=0..floor(n/2), binomial(n-k, 2k)5^k }.
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, Jul 25 2004
STATUS
approved