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 A128291 #11 Feb 11 2024 12:43:08 %S A128291 3,5,6,9,10,12,13,14,15,17,19,20,23,24,26,27,28,30,33,34,37,39,41,42, %T A128291 43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,59,60,61,62,63,65,66,69, %U A128291 71,72,73,74,77,79,80,81,82,83,84,85,86,89,91,92,94,95,96,97,98,100 %N A128291 Complement of A118248. %C A128291 Also: Numbers whose binary representation is a substring of the concatenation of the binary representation of all smaller nonnegative integers not listed earlier. - _M. F. Hasler_, Dec 29 2012 %H A128291 Nick Hobson, <a href="/A128291/a128291.py.txt">Python program for this sequence</a> %e A128291 The first term is 3, smallest integer whose binary representation "11"[2] is a substring of the concatenation of the smaller numbers 0,1,2 ~> concat(0,1,10)="0110". %e A128291 Next is 5="101"[2], which is a substring of concat(0,1,2="10",4="100") = "0110100". Note that 3, since it occurs earlier, is excluded from the list of numbers which are concatenated. - _M. F. Hasler_, Dec 29 2012 %Y A128291 Cf. A048991, A048992, A118247, A118248. %K A128291 base,easy,nonn %O A128291 0,1 %A A128291 _Nick Hobson_, Feb 24 2007