%I A089509
%S A089509 1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0,
               1,
%T A089509 1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,
%U A089509 1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0,1
%V A089509 1,1,1,1,-1,1,0,1,1,-1,-1,1,-1,0,-1,1,-1,1,1,-1,0,-1,-1,1,1,-1,1,0,1,-1,
               1,1,-1,-1,0,1,
%W A089509 1,1,-1,-1,-1,0,-1,-1,-1,-1,1,1,0,1,-1,-1,1,1,1,0,1,1,1,-1,-1,1,0,1,1,
               -1,-1,-1,-1,0,-1,
%X A089509 1,-1,1,1,1,0,-1,-1,-1,1,-1,1,0,1,-1,1,-1,-1,-1,0,-1,1,1,-1,1,-1,0,-1,
               1,-1,-1,1,-1,0,1
%N A089509 a(n)=Kronecker(7/n).
%F A089509 if n==0 (mod 7) a(n)=0; for p in=A003632 a(p)=-1; for p in A038878 a(p)=+1
%o A089509 (PARI) a(n)=kronecker(7,n)
%Y A089509 Cf. A091338, A080891.
%Y A089509 Sequence in context: A071027 A152904 A118102 this_sequence A157972 A124897 
               A138345
%Y A089509 Adjacent sequences: A089506 A089507 A089508 this_sequence A089510 A089511 
               A089512
%K A089509 sign
%O A089509 1,1
%A A089509 Benoit Cloitre (benoit7848c(AT)orange.fr), Jan 03 2004