%I A005151 M4779
%S A005151 1,11,21,1112,3112,211213,312213,212223,114213,31121314,41122314,
%T A005151 31221324,21322314,21322314,21322314,21322314,21322314,21322314,21322314,
%U A005151 21322314,21322314,21322314,21322314,21322314,21322314,21322314
%N A005151 Summarize the previous term! (in increasing order).
%D A005151 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, 
               Academic Press, 1995 (includes this sequence).
%D A005151 V. Bronstein and A. S. Fraenkel, On a curious property of counting sequences, 
               Amer. Math. Monthly, 101 (1994), 560-563.
%D A005151 Problem in J. Recreational Math., 30 (4) (1999-2000), p. 309.
%D A005151 C. Fleenor, "A litteral sequence", Solution to Problem 2562, Journal 
               of Recreational Mathematics, vol. 31 No. 4 pp. 307 2002-3 Baywood 
               NY.
%H A005151 Madras Math's Amazing Number Facts, <a href="http://www.users.zetnet.co.uk/
               madras/maths/amazingnofacts/fact013.html">Fact No. 13</a>
%H A005151 Madras Math, <a href="http://www.users.zetnet.co.uk/madras/maths/descriptive6.html">
               Descriptive Number</a>
%e A005151 For example, the term after 312213 is obtained by saying "Two 1's, two 
               2's, two 3's", which gives 21-22-23, i.e. 212223.
%t A005151 RunLengthEncode[x_List] := (Through[{Length, First}[ #1]] &) /@ Split[ 
               Sort[x]]; LookAndSay[n_, d_:1] := NestList[ Flatten[ RunLengthEncode[ 
               # ]] &, {d}, n - 1]; F[n_] := LookAndSay[n, 1][[n]]; Table[ FromDigits[ 
               F[n]], {n, 25}] (from Robert G. Wilson v Jan 22 2004).
%Y A005151 Cf. A005150. See A083671 for another version.
%Y A005151 Cf. A047842.
%Y A005151 Sequence in context: A092806 A138485 A006711 this_sequence A098155 A098154 
               A158081
%Y A005151 Adjacent sequences: A005148 A005149 A005150 this_sequence A005152 A005153 
               A005154
%K A005151 nonn,base,easy
%O A005151 1,2
%A A005151 N. J. A. Sloane (njas(AT)research.att.com).