if a(n)=sigma lower notation(r=0) and upper notation(n) expression to be summated (1/(nCr) then same sigma but expression to be summated (r/(nCr) equals ?? for first
if a(n)=sigma lower notation(r=0) and upper notation(n) expression to be summated (1/(nCr) then same sigma but expression to be summated (r/(nCr) equals