OFFSET
0,3
COMMENTS
Second column of A117939.
FORMULA
a(n)=sum{k=0..n, L((n-j)/3)*L(C(n,k)/3)} where L(j/p) is the Legendre symbol of j and p.
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Paul Barry, Apr 05 2006
STATUS
approved