It doesn't seem to make it especially easy: you still have the same problem of having to eliminate the multiples of 61, 79, 89, etc. which are not obvious. Yes,

It doesn't seem to make it especially easy: you still have the same problem of having to eliminate the multiples of 61, 79, 89, etc. which are not obvious. Yes, you can count, but it looks very time-consuming. The problem still stands that one needs to go in the 500,000s for that problem (thus 700s for the square root). That's still a long way to go… I'm really curious about how cperciva did it. You're supposed to find the first Fibonacci prime over 227,000. The first Fibonacci number over that is obviously not prime (multiple of 3), but the one after that is not obvious even if you have the list of primes obtained with that method.