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%I #9 Apr 30 2018 11:32:26
%S 1,11,1011,10001011,1000000010001011,10000000000000001000000010001011,
%T 1000000000000000000000000000000010000000000000001000000010001011,
%U 10000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000010000000000000001000000010001011
%N Lexicographically earliest sequence of distinct terms such that what emerges from the mask rebuilds the sequence itself, term by term (see the Comment section for the mask explanation).
%C For any pair of contiguous terms, one of the terms uses fewer digits than the other. This term is called the mask. Put the mask on the other term, starting from the left. What is not covered by the mask rebuilds, term by term, the starting sequence.
%C The n-th term of the sequence has exactly 2^(n-1) digits, which means that a(21) has more than one million digits.
%C The sequence starts with a(1) = 1, then a(n) = 10^(2^(n-1)-1)+a(n-1).
%H Jean-Marc Falcoz, <a href="/A303786/b303786.txt">Table of n, a(n) for n = 1..11</a>
%e In the pair (1,11), 1 is the mask; 1 emerges = a(1);
%e In the pair (11,1011), 11 is the mask; 11 emerges = a(2);
%e In the pair (1011,10001011), 1011 is the mask; 1011 emerges = a(3); etc.
%Y Cf. A303782 (same idea with primes), A303783 (with squares), A303784 (with even numbers), A303785 (with odd numbers).
%K nonn,base
%O 1,2
%A _Eric Angelini_ and _Jean-Marc Falcoz_, Apr 30 2018
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