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

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


are fulfilled, 5 is a good prime.
There are infinitely many good primes.[1] The first few good primes are
- 5, 11, 17, 29, 37, 41, 53, 59, 67, 71, 97, 101, 127, 149 (sequence A028388 in OEIS).
References
- ↑ Weisstein, Eric W., "Good Prime", MathWorld.
|
By formula |
|
By integer sequence |
|
By property |
|
Base-dependent |
|
Patterns |
- Twin (p, p + 2)
- Bi-twin chain (n − 1, n + 1, 2n − 1, 2n + 1, …)
- Triplet (p, p + 2 or p + 4, p + 6)
- Quadruplet (p, p + 2, p + 6, p + 8)
- k−Tuple
- Cousin (p, p + 4)
- Sexy (p, p + 6)
- Chen
- Sophie Germain (p, 2p + 1)
- Cunningham chain (p, 2p ± 1, …)
- Safe (p, (p − 1)/2)
- Arithmetic progression (p + a·n, n = 0, 1, …)
- Balanced (consecutive p − n, p, p + n)
|
By size |
|
Complex numbers |
|
Composite numbers |
|
Related topics |
|
First 100 primes |
|
|
fr:Liste de nombres premiers#Bon nombre premier