Background: For example, take problem 585, it is at a difficulty level of 38. So, computing F(5000000) is pretty hard and only 211 members have solved it at that difficulty even after the problem has been around for more than 9 years. (At some point hk mentioned that reducing parameter of the problem to computing F(50000) would completely change the problem, maybe in the sense that with some semi-intelligent brute-force the F(50000) could be computed).
So, my suggestion is for each problem can we have different difficulty levels, so instead of just solving Problem 585 for a difficulty level of 38, (only if you solve the problem at level 38 will you get credit for solving the problem); maybe we compute F(50000) and get the answer verified at Project Euler Website itself (and console ourself saying we got to 50000 at least
For problems where it makes sense, instead of a single textbox for the answer, we could have two textboxes, one for the parameters you solved the problem with (for 585, 1 <= N <= 5000000), and another textbox for the answer obtained. On submit, you will get a right or wrong message. Only if N = 5000000 will you get credit for solving the problem.

