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Length of the n-th term in the Roman numeral Look and Say sequence A098595.
2

%I #9 May 24 2024 15:20:47

%S 1,2,3,4,3,6,9,8,10,15,24,23,29,36,49,54,62,75,92,105,115,138,161,180,

%T 202,231,268,297,331,376,429,472,524,593,666,731,815,912,1017,1120,

%U 1244,1383,1536,1689,1873,2074,2291,2526,2790,3083,3398,3749,4131,4552,5023

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

%H Peter J. C. Moses, <a href="/A098596/b098596.txt">Table of n, a(n) for n = 1..1000</a>

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

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

%t 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};

%t 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};

%t gf=Fold[x #1+#2&,0,p]/Fold[x #1+#2&,0,q];

%t CoefficientList[Series[gf,{x,0,99}],x] (* _Peter J. C. Moses_, Jun 21 2013 *)

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

%K easy,less,nonn,base

%O 1,2

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

%E More terms from _David Wasserman_, Feb 26 2008