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.
%I A165819 #12 Mar 03 2018 09:47:51 %S A165819 1,6,11,28,37,22,29,120,137,83,43,92,205,59,61,496,529,291,595,167, %T A165819 169,86,183,376,793,410,437,220,925,123,125,2016,2081,1091,2211,583, %U A165819 293,1227,2471,2536,2601,339,171,2796,729,366,751,1520,3121,1586,1637,1652 %N A165819 a(n) = the smallest positive integer that, when written in binary, contains both binary n and binary 2n-1 as substrings. %C A165819 If a(n) in binary was instead to contain binary n and binary 2n+1 as substrings, then a(n) would = 2n+1 for all n. %H A165819 Rémy Sigrist, <a href="/A165819/b165819.txt">Table of n, a(n) for n = 1..10000</a> %F A165819 a(n) = A294977(n, 2*n-1). - _Rémy Sigrist_, Mar 03 2018 %Y A165819 Cf. A165820, A165821, A165822, A294977. %K A165819 base,nonn %O A165819 1,2 %A A165819 _Leroy Quet_, Sep 28 2009 %E A165819 More terms from _Carl R. White_, Oct 06 2009