This is a real story. A long long time ago, based on the "Four fours" problem, I wondered if I could do the same using exactly five 3īs, the restrictions a bit tighter: I could use only the 4 basic math operations, exponentiation, factorial, and all parentheses I may need. Besides, I didnīt disallow me to join two "3īs" to make "33".

Using this, and only this, I succeeded in writing expressions for all integers from 0 to 100.

To narrow your work, since a great number of integers can be easily obtained, can you find expressions for 47, 50, 56, 58, 64, 70, 71, 73, 74, 76, 77, 85, 88, 94, and 95?

The list of numbers I have using two 3's.  Not sure how useful some of the larger numbers will be.

0 = 3 - 3

1 = 3/3

2 = 3!/3

9 = 3*3

12 = 3!+3!

18 = 3!*3

27 = 3^3

33 = 33

36 = 3! * 3!

120 = 3!!/3!

216 = 3! ^ 3

240 = 3!!/3

714 = 3!! - 3!

717 = 3!! - 3

723 = 3!! + 3

726 = 3!! + 3!

729 = 3 ^ 3!

1440 = 3!! + 3!!

2160 = 3!! * 3

4320 = 3!! * 3!

46656 = 3! ^ 3!

362880 = (3*3)!

518400 = 3!! * 3!!

Posted by Leming on 2008-07-07 12:54:01