Note- All primes greater than 3 can be written as 6n+1 or 6n-1
But all numbers in the form of 6n+1 or 6n-1 are not primes.
https://primes.utm.edu/notes/faq/six.html
Not all primes greater than 3 can be written as 6n+1 or 6n-1
example: 120=6x20. 120-1=119 which is divisble by 7. 120+1=121 which is divisible by 11.
Note- All primes greater than 3 can be written as 6n+1 or 6n-1
But all numbers in the form of 6n+1 or 6n-1 are not primes.
https://primes.utm.edu/notes/faq/six.html
Not all primes greater than 3 can be written as 6n+1 or 6n-1
example: 120=6x20. 120-1=119 which is divisble by 7. 120+1=121 which is divisible by 11.