cp's OEIS Frontend

A098595 Roman numerals version of the Look and Say sequence (original at A005150).

%I A098595 #16 Aug 29 2023 23:00:44
%S A098595 1,11,111,1111,151,111511,111115111,51151111,1511115151,
%T A098595 111515115111511,111115111511115111115111,51151111151511551151111,
%U A098595 15111155115111511111511115151,111515111511115111115511515115111511,1111151115111115151155111511115111511115111115111,511511111551151115111115111115151151111151511551151111
%N A098595 Roman numerals version of the Look and Say sequence (original at A005150).
%C A098595 This sequence is suggested at the link given in point 7 at the bottom of the page, but it is given as: I, II, III, IIII, IIV, IIIIV, IVIIV, ... The 5th term seems to use the "number" followed by "frequency" method (one appears 4 times -> "I"//"IV") but the 6th and 7th terms use the usual "frequency"//"number" method.
%C A098595 The analog of Conway's constant for this sequence is C=1.09807850157..., the largest real root of x^17+x^16-x^14-x^13+x^11+x^10-x^8-x^7-x^6+x^4-x^2-x-1. - _Ercole S. Banani_, Jul 27 2023
%H A098595 T. Sillke, <a href="http://www.mathematik.uni-bielefeld.de/~sillke/SEQUENCES/series000">Conway sequence</a>
%F A098595 We write the Roman numerals as I, II, III, IV, V and convert the letters into 1's and 5's for the inclusion in the encyclopedia.
%e A098595 a(1)=I=1; a(2)="one I"="II"=11; a(3)=111; a(4)=1111; a(5)="four Is"="IVI"=151; and so on.
%t A098595 A098595[1] = 1; A098595[n_] := A098595[n] = FromDigits[Flatten[{Length[#1] /. {4->{1,5}, 3->{1,1,1},2->{1,1}}, First[#1]} &/@Split[IntegerDigits[A098595[n-1]]]]]; Map[A098595,Range[15]] (* _Peter J. C. Moses_, Apr 22 2013 *)
%Y A098595 Cf. A005150 for original Look and Say sequence and a number of references.
%K A098595 base,easy,nonn
%O A098595 1,2
%A A098595 Mark Hudson (mrmarkhudson(AT)hotmail.com), Sep 17 2004
%E A098595 More terms from _David Wasserman_, Feb 25 2008