The value of 2n{1.3.5.....(2n−3)(2n−1)} is
(2n)!n!
(2n)!2n
n!(2n)!
(2n−1)!n!
1.3.5......(2n−1)2n = 1.2.3.4.5.6....(2n−1)(2n)2n2.4.5.....2n
= (2n)!2n2n(1.2.3......n) = (2n)!n!
Find the value of nC0 +nC3 +nC6............................
Prove that : (2n+1)!n!=2n1.3.5....(2n−1)(2n+1)