OFFSET
0,4
FORMULA
G.f.: (2c(-x)-1)/(1-xc(-x)^3)=(1-x+xc(-x))/(1+x)=(1-2x+sqrt(1+4x))/(2(1+x)), c(x) the g.f. of A000108.
Apparently n*a(n) +(5*n-6)*a(n-1) +2*(2*n-3)*a(n-2)=0. - R. J. Mathar, Oct 25 2012
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Apr 28 2009
STATUS
approved