OFFSET
0,3
COMMENTS
Diagonal sums of A124341. Binomial transform has g.f. (1-x)/(1-x-x^2-x^3).
LINKS
FORMULA
a(n)=sum{k=0..floor(n/2), sum{j=0..n-k, (-1)^(n-k-j)*C(n-k,j)*C(k,j-k)}}
a(n) = (-1)^(n+1)*A073358(n+1). - R. J. Mathar, Feb 04 2014
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Oct 26 2006
STATUS
approved