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 A323477 #18 Feb 24 2021 16:00:16
%S A323477 1,11,112,11221,11221221,1122122122121,1122122122121221212111,
%T A323477 1122122122121221212111221212111211113,
%U A323477 1122122122121221212111221212111211113221212111211113211113141
%N A323477 Successive generations of A306211, in compressed notation.
%C A323477 "Compressed" means the separating commas have been omitted. This will only work as long as the terms of A306211 are at most 9. However, we know from Chaffin's work (see A306211) that this is true at least for the first 10228800161220 terms of A306211.
%t A323477 s[n_] := If[n == 1, {1}, s[n] = Join[s[n-1], Length /@ Split[s[n-1]]]];
%t A323477 a[n_] := FromDigits[s[n]];
%t A323477 Array[a, 9] (* _Jean-François Alcover_, Feb 24 2021 *)
%Y A323477 Cf. A306211, A306215 (lengths), A323478 (increments).
%K A323477 nonn,base
%O A323477 1,2
%A A323477 _N. J. A. Sloane_, Jan 31 2019