..I wonder if the following formula can be calculated?
$ \sum_{k=0}^m {m \choose k} {2k \choose n} $
..I wonder if the following formula can be calculated? $ \sum_{k=0}^m {m \choose k} {2k \choose n} $ 


The generating function in $n$ is $((1+t)^2+1)^m$. The case m=n is http://oeis.org/A006139. 

