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 A084390 #21 Jan 30 2016 07:02:20 %S A084390 1,4,7,11,15,18,21,24,27,73,101,104,107,111,115,118,121,124,127,173, %T A084390 323,373,1104,1107,1111,1115,1118,1121,1124,1127,1173,1323,1373,3323, %U A084390 3373,11373,13323,13373,17373,23323,23373,73373,101373,103323,103373,111373 %N A084390 a(n) is the smallest positive integer > a(n-1) with exactly n letters when spelled in English. %C A084390 This uses the conventions that "and" is never used and two-digit numbers are not used before "hundred". The sequence is labeled "finite" because there is no widely accepted naming convention for arbitrarily large numbers. - _David Wasserman_, Dec 20 2004 %H A084390 Andrew Bolt et al., <a href="https://groups.google.com/forum/?hl=en&fromgroups#!topic/rec.puzzles/22qcHJQJEOU">Maths fun</a>, rec.puzzles group. %H A084390 jaysmith et al., <a href="https://groups.google.com/forum/?hl=en&fromgroups#!topic/rec.puzzles/KpvBiiNx0i0">Number sequence - spot the pattern</a>, rec.puzzles group. %H A084390 Wikipedia, <a href="https://en.wikipedia.org/wiki/English_numerals">English numerals</a> %e A084390 a(5) = 7 because 'seven' has 5 letters. %Y A084390 Cf. A080777. %K A084390 easy,nonn,word,fini %O A084390 3,2 %A A084390 James Ong (blackshadowshade(AT)yahoo.com.au), Jun 27 2003 %E A084390 More terms from _David Wasserman_, Dec 20 2004