%I A071859
%S A071859 0,0,1,1,1,1,0,0,1,1,1,1,0,0,1,1,1,1,2,2,3,3,1,1,2,2,1,1,1,1,0,0,1,1,1,
%T A071859 1,2,2,1,1,3,3,2,2,1,1,1,1,0,0,1,1,1,1,0,0,1,1,1,1,0,0,1,1,1,1,2,2,3
%V A071859 0,0,-1,1,1,-1,0,0,1,1,-1,-1,0,0,-1,1,1,1,-2,2,3,-3,-1,1,-2,-2,1,1,1,-1,
               0,0,1,1,-1,1,
%W A071859 2,-2,-1,-1,3,3,-2,-2,-1,1,-1,-1,0,0,1,-1,-1,1,0,0,1,1,-1,-1,0,0,-1,1,
               1,1,-2,2,3
%N A071859 Determinant of M_n where M_n is the n X n matrix m_(i,j) = A010060(i+j).
%C A071859 a(n)=0 for n=1,2,7,8,13,14,31,32,49,50,55,56,61,62...hence if a(n)=0, 
               n odd it seems that a(n+1)=0. It seems also that if a(n)=0 (n odd 
               ) then n == 1 mod 6 (converse doesn't hold).
%o A071859 (PARI) for(n=1,70,print1(matdet(matrix(n,n,i,j,length(binary(j+i))%2)),
               ","))
%Y A071859 Cf. A010060.
%Y A071859 Sequence in context: A068460 A143797 A079729 this_sequence A105899 A135695 
               A071434
%Y A071859 Adjacent sequences: A071856 A071857 A071858 this_sequence A071860 A071861 
               A071862
%K A071859 easy,more,sign
%O A071859 1,19
%A A071859 Benoit Cloitre (benoit7848c(AT)orange.fr), Jun 09 2002