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A118628 "Say what you see".

%I A118628 #24 Feb 24 2024 01:16:00
%S A118628 3,13,1113,3113,2123,112213,312213,212223,114213,31121314,41122314,
%T A118628 31221324,21322314,21322314,21322314,21322314,21322314,21322314,
%U A118628 21322314,21322314,21322314,21322314,21322314,21322314,21322314,21322314,21322314,21322314,21322314
%N A118628 "Say what you see".
%H A118628 Madras College, <a href="http://www.madras.fife.sch.uk/departments/Mathematics/activities/descriptive%20numbers/descriptive6.html">Descriptive Numbers</a>
%F A118628 a(n) = 21322314 for n > 12; a(n) = A005151(n) for n > 6. - _Reinhard Zumkeller_, Jan 26 2014
%F A118628 a(n) = A047842(a(n-1)). - _Pontus von Brömssen_, Jun 04 2023
%e A118628 3 = "one three" --> 13
%e A118628 13 = "one one, one three" --> 1113
%e A118628 1113 = "three ones, one three" --> 3113
%e A118628 3113 = "two ones, two threes" --> 2123
%o A118628 (Haskell)
%o A118628 import Data.List (group, sort, transpose)
%o A118628 a118628 n = a118628_list !! (n-1)
%o A118628 a118628_list = 3 : f [3] :: [Integer] where
%o A118628    f xs = (read $ concatMap show ys) : f (ys) where
%o A118628           ys = concat $ transpose [map length zss, map head zss]
%o A118628           zss = group $ sort xs
%o A118628 -- _Reinhard Zumkeller_, Jan 26 2014
%Y A118628 Cf. A005151.
%Y A118628 Cf. A047842, A023989.
%K A118628 nonn
%O A118628 1,1
%A A118628 _Parthasarathy Nambi_, May 09 2006