What are the next two numbers in the following series?
2, 3, 5, 11, 23, 29, 41, 53, _ , _ .
Also mention the rule that the numbers follow.
2, 3, 5, 11, 23, 29, 41, 53,
83,
89...
According to the
On-Line Encyclopedia of Integer Sequences, these are the first few
Sophie Germain primes.
Sophie Germain primes are those numbers
p that are not only prime, but where
2p+1 is also prime.
p 2p+1
002 005 is prime
003 007 is prime
005 011 is prime
007 015 is not prime
011 023 is prime
013 027 is not prime
017 035 is not prime
019 039 is not prime
023 047 is prime
029 059 is prime
031 063 is not prime
037 075 is not prime
041 083 is prime
043 087 is not prime
047 095 is not prime
053 107 is prime
059 119 is not prime
061 123 is not prime
067 135 is not prime
071 143 is not prime
073 147 is not prime
079 159 is not prime
083 167 is prime
089 179 is prime
Solution (spoiler... I cheated)
