Power's of 2 in pascal's triangle

Review

Pascal's Triangle

Pascal's Triangle is a triangular array of numbers where each number is the sum of the two numbers above it. It Looks something like this:

      1
     1 1
    1 2 1
   1 3 3 1
  1 4 6 4 1

And on and on...

Patterns and properties

Conbanations

Pascal's Triangle can also be written like this

And on and on... Remember that where .

Sum of rows

                1     =1
               1+1    =2
              1+2+1   =4
             1+3+3+1  =8
            1+4+6+4+1 =16

These are powers of two. Let's prove it true. (Note: There are dozens of more patterns but it would have nothing to do with powers of two).