%I #10 Feb 02 2021 22:47:57
%S -1,-1,4,1000000000000000000000000000000000000,100,400,300,44,24,74,
%T 15000,13000,104,404,304,4004,1100,144,124,174,324,374,3024,3074,1104,
%U 1404,3404,3304,1144,1124,1174,1324,1374,3324,3374,11374,13324,13374,17374,23324,23374
%N a(n) is the smallest number whose English name has the letter "u" in the n-th position, or -1 if no such number exists.
%H Wikipedia, <a href="https://simple.wikipedia.org/wiki/Names_for_large_numbers">Names for large numbers.</a>
%e a(3)=4 ("foUr"), a(5)=100 ("onehUndred"), a(4)=10^36 ("oneUndecillion").
%Y Cf. A164789 ("o"), A164790 ("e"), A164791 ("n"), A164792 ("t").
%Y Cf. A164793 ("i"), A164794 ("f"), A164795 ("h"), A164796 ("r").
%K word,sign
%O 1,3
%A _Claudio Meller_, Aug 26 2009
%E a(4) corrected, and a(27) and beyond from _Michael S. Branicky_, Feb 02 2021