%I A156249
%S A156249 1,1,0,1,1,1,0,2,1,3,1,2,1,3,2,3,1,3,2,4,3,4,2,4,3,4,2,3,1,2,1,3,1,2,
%T A156249 0,1,0,2,0,1,1,1,0,2,0,1,1,0,1,1,0,1,1,1,0,2,1,2,0,2,1,3,2,4,2,3,2,
%U A156249 4,3,5,4,5,3,5,4,6,4,5,4,6,5,7,5,6,4,6,5,6,4,5,3,5,4,5,3,4,3,5,3,4
%V A156249 -1,1,0,1,-1,1,0,2,1,3,1,2,1,3,2,3,1,3,2,4,3,4,2,4,3,4,2,3,1,2,1,3,1,2,
%W A156249 0,1,0,2,0,1,-1,1,0,2,0,1,-1,0,-1,1,0,1,-1,1,0,2,1,2,0,2,1,3,2,4,2,3,2,
%X A156249 4,3,5,4,5,3,5,4,6,4,5,4,6,5,7,5,6,4,6,5,6,4,5,3,5,4,5,3,4,3,5,3,4
%N A156249 a(n)=sum(k=1,n,(-1)^k*A000002(2*k-1))
%Y A156249 Sequence in context: A108103 A111376 A157226 this_sequence A164677 A001511 
               A065704
%Y A156249 Adjacent sequences: A156246 A156247 A156248 this_sequence A156250 A156251 
               A156252
%K A156249 sign
%O A156249 1,8
%A A156249 Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 07 2009