- #1

- 580

- 0

## Homework Statement

[tex]\sum^{n}_{r=0} (2r+1) (^{n} C_{r})^{2}[/tex]

## The Attempt at a Solution

[tex]x(1+x^{2})^{n}[/tex]

If I differentiate this and put x=1;

I will get the above series without the squares of the binomial coefficients.Will multiplying by [tex](1+x)^{n}[/tex] help now?