If (1+x)n=C0+C1x+C2x2+…+Cnxn, then ∑∑0≤r<s≤n(r+s)(Cr+Cs+CrCs) is equal to
If (1+x)n=C0+C1x+C2x2+.......+Cnxn, then C1C0+2C2C1+3C3C2+........+nCnCn−1=