A good prime is a prime number whose square is greater than the product of any two primes at the same number of positions before and after it in the sequence of primes.
A good prime satisfies the inequality
p
n
2
>
p
(
n
−
i
)
⋅
p
(
n
+
i
)
for all 1 ≤ i ≤ n−1. pn is the nth prime.
Example: The first primes are 2, 3, 5, 7 and 11. As for 5 both possible conditions
5
2
>
3
⋅
7
5
2
>
2
⋅
11
are fulfilled, 5 is a good prime.
There are infinitely many good primes. The first few good primes are
5, 11, 17, 29, 37, 41, 53, 59, 67, 71, 97, 101, 127, 149 (sequence
A028388 in the OEIS).