OFFSET
1,1
COMMENTS
Primes p such that 4*p^2 is in A308268.
Other than 2, all terms == 1 (mod 6).
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3) = 19 is in the sequence because 19 and 2*19^2 + 2*19 - 9 = 751 are prime.
MAPLE
select(p -> isprime(p) and isprime(2*p^2 + 2*p - 9), [2, seq(i, i=7..1000, 6)]);
MATHEMATICA
Select[Prime[Range[600]], PrimeQ[2#^2+2#-9]&] (* Harvey P. Dale, Jun 14 2021 *)
PROG
(Magma) [p:p in PrimesUpTo(5000)|IsPrime(2*p^2 + 2*p - 9)]; Marius A. Burtea, May 17 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Robert Israel, May 17 2019
STATUS
approved