There is a way to express 64 with only two fours and no symbols beyond +, -, *, /, ^, √, !, and parenthesis, although some may be used more than once. It isn't too hard. Can you find it?

It is asserted in a reliable source that 64 can also be expressed with a single 4 using 57 square root signs, nine factorials (no double or higher factorials), and 18 sets of parentheses. I can't figure it out. Can you?

(In reply to Solution to first part by Dej Mar)

The subfactorial is a pretty obscure function.  I've never even heard of it until I googled it a minute ago.
It seems to me like mathematicians are trying to squeeze as many functions into a single symbol as possible.

Posted by Tristan on 2006-04-07 22:59:59