%I #27 May 21 2024 01:16:26
%S 1,11,21,1211,111221,1012211,1110112221,101102110211,
%T 111021101221101221,1011012211011222110112211,
%U 1110211011222110211022110212221,10110122110211022110122110222110121110211
%N Describe the previous term (in base 3)!.
%H John Cerkan, <a href="/A001388/b001388.txt">Table of n, a(n) for n = 1..23</a>
%H Greg Dresden and Jacob Siehler, <a href="https://arxiv.org/abs/2405.11103">Look, There's More to Say about Conway's Look and Say sequence</a>, arXiv:2405.11103 [math.CO], 2024.
%e To get the 6th term, for example, note that the 5th term has three (10 in ternary!) 1's, two (2) 2's and one (1) 1, giving 10 1 2 2 1 1.
%t a[1] := 1; a[n_] := a[n] = FromDigits[Flatten[{IntegerDigits[Length[#],3], First[#]}& /@ Split[IntegerDigits[a[n-1]]]]]; Map[a,Range[25]] (* _Peter J. C. Moses_, Mar 24 2013 *)
%Y Cf. A005150.
%K nonn,base,easy
%O 1,2
%A _Thomas L. York_