A001388 Describe the previous term (in base 3)!.

1, 11, 21, 1211, 111221, 1012211, 1110112221, 101102110211, 111021101221101221, 1011012211011222110112211, 1110211011222110211022110212221, 10110122110211022110122110222110121110211

Offset: 1

Author

Thomas L. York

Keywords

• nonn
• base
• easy

Examples

			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.
		

Links

• John Cerkan, Table of n, a(n) for n = 1..23
• Greg Dresden and Jacob Siehler, Look, There's More to Say about Conway's Look and Say sequence, arXiv:2405.11103 [math.CO], 2024.

Crossrefs

Cf. A005150.

Programs

Mathematica

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 *)