A

number is an Eban number if, when written in words, it does not contain the letter "e". The Eban

number sequence is the series of

positive integers which do not have a letter "

e" when written in words:

2, 4, 6, 30, 32, 34, 36, 40, 42, 44, 46, 50, 52, 54, 56, 60...

two, four, six, thirty, thirty-two, thirty-four, thirty-six...

This can exclude a surprisingly large number of integers. There are no Eban numbers between
66 and 2000 (reason: "on__e__ thousand and..."), for example.

(ref: The Online Encyclopedia of Integer Sequences at http://www.research.att.com/~njas/sequences/)