OK, each person may post 1 number, the next one from previous post. Also say something about the number, say 10: Ah! 10! The first number with 2 digits. See how quick it'll take to get to 100
I believe this has to continue with 37? Then 37 it is, what you'd get by six squared plus one... or, to be more original, the approximate number of weeks a pregnant woman has to wait before giving birth to a child... or two... or three, or whatever, you get the point.