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%I #14 Nov 15 2016 12:13:52
%S 11,21,31,1115,15,1511,1521,1531,11110,110,11011,11021,11031,1101115,
%T 11015,1101511,1101521,1101531,11011110,210,21011,21021,21031,2101115,
%U 21015,2101511,2101521,2101531,21011110,310,31011,31021,31031,3101115,31015,3101511
%N Counting integers normally (1, 2, 3, 4, 5...), write them as roman numerals (I, II, III, IV, V...), describe them (one 1, two 1s, three 1s, one 1 one 5, one 5...), and write them out as numbers (11, 21, 31, 1115, 15...).
%H David Consiglio, Jr., <a href="/A180105/b180105.txt">Table of n, a(n) for n = 1..3999</a>
%H David Consiglio, Jr., <a href="/A180105/a180105.txt">Python program</a>
%e For n=9, IX gives one 1 and one 10, so a(9) = 11110.
%t f[n_] := Block[{w = RomanNumeral@ n}, FromDigits@ Flatten[IntegerDigits /@ {Length@ #, FromRomanNumeral@ First@ #} & /@ Split@ StringPartition[w, 1]]]; Array[f, {36}] (* _Michael De Vlieger_, Oct 13 2015, Version 10.2 *)
%K nonn,base
%O 1,1
%A Saiichi Shayan Hashimoto (drako3759(AT)gmail.com), Aug 09 2010
%E a(9) and a(19) corrected by _David Consiglio, Jr._, Oct 12 2015
%E More terms from _David Consiglio, Jr._, Oct 12 2015