%I M5122 N2218 #29 Jan 13 2023 21:13:02
%S 1,21,21000,101,121,1101,1121,21121,101101,101121,121121,1101121,
%T 1121121,21121121,101101121,101121121,121121121,1101121121,1121121121,
%U 21121121121,101101121121,101121121121,121121121121,1101121121121,1121121121121,21121121121121
%N Smallest natural number requiring n words in English (as spoken in England).
%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H Robert G. Wilson v, <a href="/A000027/a000027.txt">American English names for the numbers from 0 to 11159 without spaces or hyphens</a>.
%e One, twenty-one, twenty-one thousand, one hundred and one, one hundred and twenty-one, ...
%K nonn,word
%O 1,2
%A _N. J. A. Sloane_
%E Edited by _N. J. A. Sloane_, Jul 05 2008
%E a(20) and beyond from _Michael S. Branicky_, Jan 13 2023