But wait. To solve an NP problem of size n, you need square(n) atoms. But 40 atoms is barely more than 36, so you can solve a NP problem of size 6, which is easy and possible.
I think brute force on an NP problem is factorial(n) So factorial(6) == 6 ! == 6 * 5 * 4 * 3 * 2 * 1 == 720.
Am I misunderstanding something here ?