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 A164789 #13 Apr 21 2023 11:45:03
%S A164789 1,4,2,0,4000000000000000000000000000,41,21,24,22,72,101,104,102,304,
%T A164789 302,141,121,124,122,172,322,372,1104,1102,1304,1302,1141,1121,1124,
%U A164789 1122,1172,1322,1372,3322,3372,11372,13322,13372,17372,23322,23372,73372,101372,103322,103372
%N A164789 a(n) is the smallest number which has in its English name the letter "o" in the n-th position, or -1 if no such number exists.
%e A164789 a(1)=1 ("One"), a(2)=4 ("fOur"), a(3)=2 ("twO"), a(4)=0 ("zerO"), a(5)=4*10^27 ("fourOctillion").
%Y A164789 Cf. A164790 ("e"), A164791 ("n"), A164792 ("t"), A164793 ("i").
%Y A164789 Cf. A164794 ("f"), A164795 ("h"), A164796 ("r"), A164797 ("u").
%K A164789 word,sign
%O A164789 1,2
%A A164789 _Claudio Meller_, Aug 26 2009
%E A164789 a(5) corrected and a(23) and beyond from _Michael S. Branicky_, Mar 25 2021