i found up that my equetion is wrong

since n/ln(n) equals the number of primes between zero and n

and betwin n and 2n there is always a prime

u can take only the primes n/2 n/4 and n/8

in case that n is big enough and each one of them have been lowered to lowest number in range (2~2n)

their multifaction is n^3/64 which is much bigger from n^2 from n>64