The four integers after 13 are well defined, the 5th might be controversial.
Please comment.
Smallest natural number requiring n letters in English,starts with "one" (3 letters).
Edited on September 1, 2015, 11:31 pm
blackjack
<a href="http://c.casalemedia.com/c?s=51816&f=3&id=0" target="_blank"><img src="http://as.casalemedia.com/s?s=51816&u=http://perplexus.info&f=3&id=0&if=0" width="120" height="600" border="0"></a>
flooble's webmaster puzzle
spoiler: Official solution