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 A363054 #44 Dec 20 2024 10:59:14
%S A363054 20,1210,11121110,31123110,132112132110,11131221121113122110,
%T A363054 311311222112311311222110,1321132132211213211321322110,
%U A363054 11131221131211132221121113122113121113222110,3113112221131112311332211231131122211311123113322110
%N A363054 Look and say sequence: describe the previous term (method A, starting with 20).
%H A363054 Michael De Vlieger, <a href="/A363054/b363054.txt">Table of n, a(n) for n = 1..21</a>
%H A363054 Julia Witte Zimmerman, Denis Hudon, Kathryn Cramer, Alejandro J. Ruiz, Calla Beauregard, Ashley Fehr, Mikaela Irene Fudolig, Bradford Demarest, Yoshi Meke Bird, Milo Z. Trujillo, Christopher M. Danforth, and Peter Sheridan Dodds, <a href="https://arxiv.org/abs/2412.10924">Tokens, the oft-overlooked appetizer: Large language models, the distributional hypothesis, and meaning</a>, arXiv:2412.10924 [cs.CL], 2024. See pp. 21, 28.
%e A363054 The term after 1210 is given by saying "I see one 1, one 2, one 1, and one 0", and then writing down the digits as 11-12-11-10, yielding 11121110.
%t A363054 NestList[FromDigits@ Flatten@ Map[Reverse@ Tally[#][[1]] &, Split@ IntegerDigits[#] ] &, 20, 12] (* _Michael De Vlieger_, Jul 05 2023 *)
%o A363054 (Python)
%o A363054 from itertools import count, groupby, islice
%o A363054 def LS(n): return int(''.join(str(len(list(g)))+k for k, g in groupby(str(n))))
%o A363054 def agen(an=20): yield an; yield from (an:=LS(an) for n in count(1))
%o A363054 print(list(islice(agen(), 10))) # _Michael S. Branicky_, May 15 2023
%Y A363054 Other look-and-say sequences: A005150, A001155, A006751, A006715, A001140, A001141, A001143, A001145, A001151, A007651, A001387, A098595, A045918.
%K A363054 nonn,base
%O A363054 1,1
%A A363054 _Julia Zimmerman_, May 15 2023