%I A117946
%S A117946 0,1,2,0,2,4,0,1,2,0,2,4,0,4,8,0,2,4,0,1,2,0,2,4,0,1,2,0,2,4,0,4,8,0,2,
%T A117946 4,0,4,8,0,8,16,0,4,8,0,2,4,0,4,8,0,2,4,0,1,2,0,2,4,0,1,2,0,2,4,0,4,8,
               0,
%U A117946 2,4,0,1,2,0,2,4,0,1,2,0,2,4,0,4,8,0,2,4,0,4,8,0,8,16,0,4,8
%V A117946 0,1,-2,0,2,-4,0,1,-2,0,2,-4,0,4,-8,0,2,-4,0,1,-2,0,2,-4,0,1,-2,0,2,-4,
               0,4,-8,0,2,-4,0,
%W A117946 4,-8,0,8,-16,0,4,-8,0,2,-4,0,4,-8,0,2,-4,0,1,-2,0,2,-4,0,1,-2,0,2,-4,
               0,4,-8,0,2,-4,0,
%X A117946 1,-2,0,2,-4,0,1,-2,0,2,-4,0,4,-8,0,2,-4,0,4,-8,0,8,-16,0,4,-8
%N A117946 a(3n)=0, a(3n+1)/a(1)=a(3n+2)/a(2)=A059151(n).
%C A117946 Second column of A117939.
%F A117946 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.
%Y A117946 Sequence in context: A099040 A136717 A136716 this_sequence A061930 A141660 
               A115273
%Y A117946 Adjacent sequences: A117943 A117944 A117945 this_sequence A117947 A117948 
               A117949
%K A117946 easy,sign
%O A117946 0,3
%A A117946 Paul Barry (pbarry(AT)wit.ie), Apr 05 2006