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 A189799 #17 Jul 17 2017 03:53:47 %S A189799 1,1,3,19,1,4,3,19,24,50,1,18,4,3,7,86,19,44,24,50,56,16,1,18,23,49,4, %T A189799 42,3,8,7,177,86,185,19,100,44,52,24,225,50,478,56,16,47,1,5,85,18,43, %U A189799 23,49,55,15,4 %N A189799 Least position k of n (n written in base 2) in the infinite string 101110111110111101100011001110111... (i.e., 23571113171923... in base 2). %e A189799 1 appears as (1)0111..., 2 appears as (10)111011..., 3 as 10(11)10111..., 4 as 101110111110111101(100)0... %p A189799 A189799 := proc(n) %p A189799 local abin ,nbin ,nlen; %p A189799 abin := ListTools[Reverse](convert(A154703(100),base,10)) ; %p A189799 nbin := ListTools[Reverse](convert(n,base,2)) ; %p A189799 nlen := nops(nbin) ; %p A189799 for i from 1 do %p A189799 if verify(nbin,[op(i..i+nlen-1,abin)],'sublist') then %p A189799 return i; %p A189799 end if; %p A189799 end do: %p A189799 return 0 ; %p A189799 end proc: %p A189799 seq(A189799(n),n=1..55) ; # _R. J. Mathar_, Jun 07 2011 %Y A189799 Cf. A004676, A007088, A154703. %K A189799 nonn,base %O A189799 1,3 %A A189799 _Juri-Stepan Gerasimov_, May 24 2011 %E A189799 Corrected by _R. J. Mathar_, Jun 07 2011