Factorial Primes
Basic Info
Discovered by N/A
Number of Conjectured infinite
Description A prime which is either one more or one less than a factorial
First Few 2, 3, 5, 7, 11, 13, 23, 719

Factorial Primes are prime numbers that can be expressed in the form n!±1, ie they are prime numbers that are one bigger or smaller than a factorial number. A factorial number is a number that is made by multiplying consecutive numbers, starting with 1, eg 4!=1*2*3*4. Both 11 and 13 are factorial primes because they complete the rule 4!±1.

The First Few Factorial Primes

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