Sum of two middle terms in the expansion of (1+x)2n−1 is

Two middle terms in the expansion of (1+x)2n−1are 2n−1+12 th and 2n−1+12+1 th  terms, that is, nth and (n+1)th termsCoefficients of the middle terms in the expansion of (1+x)2n−1 are  2n−1Cn−1 and 2n−1Cn  and theirSum  =2n−1Cn−1   +2n−1Cn=2nCn