cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A093382 a(n) = length k of longest binary sequence x(1) ... x(k) such that for no n <= i < j <= k/2 is x(i) ... x(2i) a subsequence of x(j) ... x(2j).

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%I A093382 #19 May 25 2024 07:10:48
%S A093382 11,31,199
%N A093382 a(n) = length k of longest binary sequence x(1) ... x(k) such that for no n <= i < j <= k/2 is x(i) ... x(2i) a subsequence of x(j) ... x(2j).
%C A093382 Doesn't the binary sequence 000010011001110011101010101010101010101100110 demonstrate that a(2) >= 45? - _R. J. Mathar_, Jul 29 2007 Answer: No - see the following comment.
%C A093382 The sequence of length 45 above does not satisfy the requirements of the definition: Subsequences are not required to be consecutive. Therefore it cannot show a(2) >= 45. In the sequence we find for i=2, j=3: x(i..2i) is 000; x(j..2j) is 001001; and 000 is a subsequence of 001001. - _Don Reble_, May 13 2008
%C A093382 a(4) >= 376843. - _Bert Dobbelaere_, May 25 2024
%D A093382 a(1) - a(3) computed by R. Dougherty, who finds that a(4) >= 187205.
%H A093382 H. M. Friedman, <a href="http://dx.doi.org/10.1006/jcta.2000.3154">Long finite sequences</a>, J. Comb. Theory, A 95 (2001), 102-144.
%e A093382 a(1) = 11 from 01110000000.
%Y A093382 See A093383-A093386 for illustrations of a(2) and a(3). Cf. A014221, A094091.
%K A093382 nonn,bref,nice,more
%O A093382 1,1
%A A093382 _N. J. A. Sloane_, Apr 29 2004