Find the value of `sumsum_(0lt=i

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

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

Find the sum sumsum_(0leiltjlen)"^nC_i

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

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