%I A143222
%S A143222 0,1,1,0,1,0,0,1,1,0,0,1,0,0,1,1,1,1,0,0,0,1,1,1,0,0,0,1,0,1,0,1,1,1,0,
%T A143222 0,0,1,0,0,1,0,1,0,1,1,0,1,1,0,0,1,0,1,0,1,0,1,1,1,0,1,1,1,1,1,1,1,0,0,
%U A143222 1,0,1,0,0,1,0,1,1,0,1,1,0,0,1,0,0,0,1,0,1,0,0,0,1,0,1,1,0,0,0,0,1,1,1
%N A143222 a(0)=0. For n >=1, a(n) = 0 if the binary representation of n occurs 
               at least once in the concatenation of (a(0),a(1),...,a(n-1)). a(n) 
               = 1 otherwise.
%H A143222 Leroy Quet, <a href="http://www.prism-of-spirals.net/">Home Page</a> 
               (listed in lieu of email address)
%e A143222 The binary representation of 20 is 10100. This occurs in the concatenation 
               of terms a(0) through a(19) like so: 01(10100)1100100111100. So a(20) 
               = 0.
%t A143222 f[l_List]:=Append[l,Boole[StringPosition[ToString[FromDigits[l]],ToString[FromDigits[IntegerDigits[Length[l],
               2]]]]=={}]];Nest[f,{0},125] [From Ray Chandler (rayjchandler(AT)sbcglobal.net), 
               Nov 09 2008]
%Y A143222 Cf. A143220, A143221.
%Y A143222 Sequence in context: A029691 A053866 A156595 this_sequence A010060 A118247 
               A122257
%Y A143222 Adjacent sequences: A143219 A143220 A143221 this_sequence A143223 A143224 
               A143225
%K A143222 base,nonn
%O A143222 0,1
%A A143222 Leroy Quet, Jul 30 2008
%E A143222 Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Nov 09 2008