This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A231072 #6 Nov 05 2013 06:29:59
%S A231072 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,2,2,2,2,2,2,2,2,2,1,2,2,2,
%T A231072 2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2,2,2,
%U A231072 2,2,1,2,2,2,2,2,2,2,2,2,1,2,2,2,2,2
%N A231072 Number of words in English spelling of n.
%C A231072 From a(101) on it must be made precise that this sequence uses the American style ("one hundred one"), as in A052360, and not the British style ("one hundred and one"). The choice of long or short scale does not make a difference since, e.g., the word "milliard" in long scale use would simply be replaced by "billion" in short scale. However, the use of "thousand [million]" instead, would lead to different results for numbers such that floor(n/10^6) mod 10^3 is zero. - _M. F. Hasler_, Nov 03 2013
%H A231072 <a href="/index/El#English">Index to OEIS: sequences related to English words for n</a>
%e A231072 From "zero" to "twenty", the numbers are written in one word, so a(0..20)=1. "Twenty-one" is the first term to require 2 words, so a(21)=2.
%o A231072 (PARI) a(n)=sum(k=7,#n=Vecsmall(English(n)),n[k-3]<65)+1 \\ See A052360 for English(). Only characters 4,...,length-4 need to be checked for space/hyphen since there is no word with less than 3 letters.
%Y A231072 Cf. A001167, A075774, A052360.
%K A231072 nonn,word,easy
%O A231072 0,22
%A A231072 _M. F. Hasler_, Nov 03 2013