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 A045998 #9 Oct 10 2019 03:56:28 %S A045998 1,11,1,1011,111001,110011,10001,10111011,1110111001,1110110011, %T A045998 1110010001,1100111011,100111001,101100110011,11100100010001, %U A045998 11001110111011,1001110111001,1011001110110011,111001001110010001 %N A045998 Binary Gleichniszahlen-Reihe (BGR) sequence: describe previous term (cf. A005150), reduce number of digits seen mod 2 (then for the purposes of this data-base, discard leading zeros). %C A045998 Terms with a leading zero: a(2), a(6), a(12), a(16), a(20), a(28), a(32), a(36), a(40), a(44), a(48), a(60), ... %D A045998 N. Worrick, S. Lewis and B. Shrader, A possible formula for the length of BGR sequences, Graph Theory Notes of New York, XXXVI (1999), p. 25. %e A045998 1, 11, 01, 1011, 111001, 110011, 010001, ... (after 110011, next term is 212021 -> 010001 -> 10001). %Y A045998 Cf. A005150, A045999, A048522. %K A045998 nonn,base,easy %O A045998 0,2 %A A045998 _N. J. A. Sloane_ %E A045998 More terms from _Patrick De Geest_, Jun 15 1999