(1+ 1/2)(1+ 1/3)(1+ 1/4)...(1+ 1/n)=(3/2)(4/3)(5/4)...[(n+1)/n]=[3·4·5·...·(n+1)]/(2·3·4·...·n)=(n+1)/2
(1+1/2)*(1+1/3)*(1+1/4)*……*(1+1/n)=(3/2)(4/3)(5/4)......[(n+1)/n]=(n+1)/2
