$f(m,n)=\binom{m}{m}\binom{n}{1}+\binom{m}{m1}\binom{n}{2}+\cdots+\binom{m}{2}\binom{n}{m1}+\binom{m}{1}\binom{n}{m}=?$
Can we simplify the expression above?
$f(m,n)=\binom{m}{m}\binom{n}{1}+\binom{m}{m1}\binom{n}{2}+\cdots+\binom{m}{2}\binom{n}{m1}+\binom{m}{1}\binom{n}{m}=?$ Can we simplify the expression above? 

closed as too localized by Ben Webster♦ Oct 2 '10 at 3:51This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question. 

