The Most Boring Number.

As of this past March, 20,067 was the smallest number that did not appear in any of the OEIS's stored number sequences. (This is because the database stores only the first 180 or so characters of a number sequence, however; otherwise every number would appear in the OEIS's list of positive integers.) To substantiate this, they ran what is known as a Monte Carlo simulation: they designed a function that maps natural numbers to other natural numbers - and does so in such a way that small numbers are output more often than larger ones. [Extracted from the article]