A098595 -id:A098595 - cp's OEIS frontend

A098596 Length of the n-th term in the Roman numeral Look and Say sequence A098595.

1, 2, 3, 4, 3, 6, 9, 8, 10, 15, 24, 23, 29, 36, 49, 54, 62, 75, 92, 105, 115, 138, 161, 180, 202, 231, 268, 297, 331, 376, 429, 472, 524, 593, 666, 731, 815, 912, 1017, 1120, 1244, 1383, 1536, 1689, 1873, 2074, 2291, 2526, 2790, 3083, 3398, 3749, 4131, 4552, 5023

Offset: 1

Mark Hudson (mrmarkhudson(AT)hotmail.com), Sep 17 2004

			The 7th term in A098595 = 111115111 so a(7)=9.

Peter J. C. Moses, Table of n, a(n) for n = 1..1000

Cf. A098595. A005150 for original Look and Say sequence.

p={4,8,10,10,10,10,6,2,-4,-8,-10,-10,-6,-9,-13,-14,-4,8,21,28,27,18,13,23,39,50,49,43,34,26,27,35,43,40,29,15,7,3,4,9,14,14,9,4,1};
q={-1,-2,-3,-2,1,4,5,3,-1,-4,-3,1,5,5,1,-4,-6,-3,2,5,4,0,-4,-5,-3,0,2,2,1};
gf=Fold[x #1+#2&,0,p]/Fold[x #1+#2&,0,q];
CoefficientList[Series[gf,{x,0,99}],x] (* Peter J. C. Moses, Jun 21 2013 *)

a(n) = length(A098595(n)).

More terms from David Wasserman, Feb 26 2008

A363054 Look and say sequence: describe the previous term (method A, starting with 20).

Original entry on oeis.org

20, 1210, 11121110, 31123110, 132112132110, 11131221121113122110, 311311222112311311222110, 1321132132211213211321322110, 11131221131211132221121113122113121113222110, 3113112221131112311332211231131122211311123113322110

Offset: 1

Julia Zimmerman, May 15 2023

			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.

Michael De Vlieger, Table of n, a(n) for n = 1..21
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, Tokens, the oft-overlooked appetizer: Large language models, the distributional hypothesis, and meaning, arXiv:2412.10924 [cs.CL], 2024. See pp. 21, 28.

Other look-and-say sequences: A005150, A001155, A006751, A006715, A001140, A001141, A001143, A001145, A001151, A007651, A001387, A098595, A045918.

NestList[FromDigits@ Flatten@ Map[Reverse@ Tally[#][[1]] &, Split@ IntegerDigits[#] ] &, 20, 12] (* Michael De Vlieger, Jul 05 2023 *)

from itertools import count, groupby, islice
def LS(n): return int(''.join(str(len(list(g)))+k for k, g in groupby(str(n))))
def agen(an=20): yield an; yield from (an:=LS(an) for n in count(1))
print(list(islice(agen(), 10))) # Michael S. Branicky, May 15 2023

cp's OEIS Frontend

A098596 Length of the n-th term in the Roman numeral Look and Say sequence A098595.

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