Find the sum `sumsum_(0leiltjlen)"^nC_i`

Find the sumsum_(0leiltjlen)1 .

Find the sum sumsum_(0lt=ilt=jlt=n)^ nC_i^n C_j

Find the sum sumsum_(i!=j)^ nC_i^n C_j

If a_(n) = sum_(r=0)^(n) (1)/(""^(n)C_(r)) , then the value of (sumsum)_(0leiltjlen) (i/(""^(n)C_(i))+j/(""^(n)C_(j)))

Find the value of sumsum_(0lt=i

The sum sumsum_(0leilejle10) (""^(10)C_(j))(""^(j)C_(r-1)) is equal to

Find the value of sumsum_(1leilejlt=n-1)(ij)^n c_i^n"" c_jdot

If (1+x)^n=C_0+C_1x+C_2x^2+.......+C_n x^n , then show that the sum of the products of the coefficients taken two at a time, represented by sumsum_(0lt=iltjlt=n) "^nc_i "^n c_j is equal to 2^(2n-1)-((2n)!)/ (2(n !)^2)

The value of the expansion (sumsum)_(0 le i lt j le n) (-1)^(i+j-1)"^(n)C_(i)*^(n)C_(j)=

Find the sum sum_(j=0)^(n) (""^(4n+1)C_(j)+""^(4n+1)C_(2n-j)) .