1,2

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.

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

T. Sillke, Conway sequence

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.

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.

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 *)

Cf. A005150 for original Look and Say sequence and a number of references.

Sequence in context: A265380 A114397 A336325 * A273978 A334131 A077488

Adjacent sequences: A098592 A098593 A098594 * A098596 A098597 A098598

base,easy,nonn

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

More terms from David Wasserman, Feb 25 2008

approved