> A039963 and A092444 (after adjusting for offset differences) > http://www.research.att.com/~njas/sequences/?q=id:A039963|id:A092444 Yes, definitely, after adjusting for offset. It can be also described as %C A039963 The period-doubling sequence (A035263) repeated. %F A039963 Recurrence: a(4n+1) = a(4n+2) = 1, a(4n+3) = a(4n+4) = 1-a(2n). ralf