A262098 - OEIS

A262098

Primes p such that 2^p + 9 is also prime.

2, 3, 5, 7, 23, 37, 47, 263, 317, 3229, 3253

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,1

COMMENTS

a(12) > 100000. - Dana Jacobsen, Oct 03 2015

a(12) > 382198 using A057196. - Michael S. Branicky, Oct 31 2024

LINKS

EXAMPLE

5 is in sequence because 2^5 + 9 = 41 is prime.

MATHEMATICA

Select[Prime[Range[1000]], PrimeQ[2^# + 9] &]

PROG

(Magma) [p: p in PrimesUpTo(1000) | IsPrime(2^p+9)];

(PARI) for(n=1, 1e3, if(isprime((2^prime(n))+9), print1(prime(n)", "))) \\ Altug Alkan, Sep 18 2015

(Perl) use ntheory ":all"; use Math::GMP qw/:constant/; forprimes { say if is_prime(2**$_+9) } 10000; # Dana Jacobsen, Oct 03 2015

CROSSREFS

Subsequence of primes of A057196.

Cf. primes p such that 2^p+k is a prime: A057736 (k=3), A175173 (k=5), this sequence (k=9), A155780 (k=11), A175234 (k=15), A262099 (k=17), A175235 (k=21), A175236 (k=23), A262934 (k=27), A262100 (k=29), A262201 (k=33), A262962 (k=35).

KEYWORD

nonn,more,changed

AUTHOR

STATUS

approved