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 A164796 #10 Feb 02 2021 22:47:38
%S A164796 -1,-1,0,4,1000000000000,4000000000000,3000000000000,43,23,24,74,
%T A164796 24000000000000,103,104,303,304,3004,143,123,124,174,324,374,1103,
%U A164796 1104,1303,1304,3303,1143,1123,1124,1174,1324,1374,3324,3374,11374,13324,13374,17374,23324
%N A164796 a(n) is the smallest number whose English name has the letter "r" in the n-th position, or -1 if no such number exists.
%e A164796 a(3)=0 ("zeRo"), a(4)=4 ("fouR"), a(5)=1000000000000 ("onetRillion"), a(13)=103 ("onehundredthRee").
%Y A164796 Cf. A164789 ("o"), A164790 ("e"), A164791 ("n"), A164792 ("t").
%Y A164796 Cf. A164793 ("i"), A164794 ("f"), A164795 ("h"), A164797 ("u").
%K A164796 word,sign
%O A164796 1,4
%A A164796 _Claudio Meller_, Aug 26 2009
%E A164796 a(24) and beyond from _Michael S. Branicky_, Feb 02 2021