funny old google puzzle

In 2004 (yes I know, that's old news), Google issued some puzzles as recruitment adds in Dr Dobbs. I think I had found the solution to one of them, but never could find a confirmation of solution, so here goes, in hope someone will be able to confirm it :-).

I think the answer is 6. There is no underlying mathematical sequence, each number is actually a rot13'd letter, forming a word with a missing letter. They are placed like this :

5 2
14 20
26 ?

Read from right to left : 2, 5, 20, 14, ?, 26. rot13 that and you get
O, R, G, A, ? M

The solution as a ruby one-liner :


[2, 5, 20, 14, 6, 26].each { |p| puts sprintf "%c", (( (p + 13) % 26 ) + (?A - 1)) }