Sum-the-series-n-C-0-n-C-1-n-C-1-n-C-2-n-C-2-n-C-3-n-C-r-n-C-r-1-

Question Number 60416 by Tawa1 last updated on 20/May/19

Sum the series : \overset{n}{} C_{0} \overset{n}{} C_{1} + \overset{n}{} C_{1} \overset{n}{} C_{2} + \overset{n}{} C_{2} \overset{n}{} C_{3} + \dots + \overset{n}{} C_{r} \overset{n}{} C_{r + 1}