331 is the smallest number except 1 being at once both, a centered pentagonal number and a centered hexagonal number. It's also the 67th prime number. Btw I know we skipped 100 numbers but they sucked anyway.

There's also no [b][url=http://www.strangehorizons.com/2000/20001120/secret_number.shtml]bleem[/url][/b]. However maybe it's not safe for me to say that.
331 is the smallest number except 1 being at once both, a centered pentagonal number and a centered hexagonal number. It's also the 67th prime number. Btw I know we skipped 100 numbers but they sucked anyway.