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