Copyright © University of Cambridge. All rights reserved.

'Forgotten Number' printed from

Show menu

I have forgotten the number of the combination of the lock on my briefcase. I did have a method for remembering it...

It went as follows:

    The number is equal to the sum of the cubes of its own digits.

      It is a three digit number less than 500

        It is the sum of consecutive factorials.

          It is a triangle number.