%I A073089
%S A073089 0,0,1,1,1,0,0,1,1,0,1,1,0,0,0,1,1,0,1,1,1,0,0,1,0,0,1,1,0,0,0,1,1,0,1,
%T A073089 1,1,0,0,1,1,0,1,1,0,0,0,1,0,0,1,1,1,0,0,1,0,0,1,1,0,0,0,1,1,0,1,1,1,0,
%U A073089 0,1,1,0,1,1,0,0,0,1,1,0,1,1,1,0,0,1,0,0,1,1,0,0,0,1,0,0,1,1,1,0,0,1,1
%N A073089 (1/2)*(4n - 3 - Sum (k=1,n, A007400(k))).
%F A073089 Recurrence: a(1) = a(4n+2) = a(8n+7) = a(16n+13) = 0, a(4n) = a(8n+3) 
               = a(16n+5) = 1, a(8n+1) = a(4n+1).
%o A073089 (PARI) a(n)=if(n<2,0,if(n%8==1,a((n+1)/2),[1,-1,0,1,1,1,0,0,1,-1,0,1,
               1,0,0,0][(n%16)+1])) /* from R. Stephan */
%Y A073089 Cf. A007400.
%Y A073089 Sequence in context: A165560 A014306 A138150 this_sequence A011657 A072126 
               A111113
%Y A073089 Adjacent sequences: A073086 A073087 A073088 this_sequence A073090 A073091 
               A073092
%K A073089 easy,nonn
%O A073089 1,1
%A A073089 Benoit Cloitre (benoit7848c(AT)orange.fr), Aug 18 2002