The AM of 2n+1C0,2n+1C1,2n+1C2,…,2n+1Cn is
2nn
2nn+1
22nn
22n(n+1)
2n+1C0+2n+1C1+2n+1C2+…+2n+1C2n+2n+1C2n+1=22n+1
Now 2n+1C0=2n+1C2n+1, 2n+1C1=2n+1C2n…2n+1Cr=2n+1C2n−r+1
So, sum of first (n + 1 ) terms
= sum of last (n + 1 ) terms
⇒ 2n+1C0+2n+1C1+2n+1C2+…+2n+1Cn=22n⇒ 2n+1C0+2n+1C1+2n+1C2+…+2n+1Cnn+1=22n(n+1)