## A Difficult Sequence

Posted by Al Gelman under Tom (37 Responds)

This is a tough one.

What is the next number in this sequence:

1,4,9,16, …

Note: the answer is NOT 25

Posted by Al Gelman under Tom (37 Responds)

This is a tough one.

What is the next number in this sequence:

1,4,9,16, …

Note: the answer is NOT 25

Posted by Al Gelman under Tom (33 Responds)

Here is a puzzle to keep you busy on a cold winter’s night. Perhaps more than one!

The challenge is to express ANY positive integer using the number 2 precisely four times, and using only well-known mathematical symbols. (You can’t make up your own!)

Here are the first four.

1= (2+2) / (2+2)

2= (2+2) + (2+2)

3= (2 x [...]