OFFSET
1,1
COMMENTS
Also, primes of the form (p^3^m)^2 + p^3^m + 1 with prime p and nonnegative integer m, since k must be a power of 3, from the theory of cyclotomic polynomials.
LINKS
Martin Becker, Table of n, a(n) for n = 1..20000
EXAMPLE
31 = (5^1)^2 + 5^1 + 1 is in the sequence as 31 is prime and 5 is prime and 1 is a positive integer.
73 = (2^3)^2 + 2^3 + 1 is in the sequence as it is prime and 2 is prime and 3 is a positive integer.
MATHEMATICA
Select[Table[q^2 + q + 1, {q, Select[Range[1500], PrimePowerQ[#] &]}], PrimeQ] (* Amiram Eldar, Aug 16 2024 *)
PROG
(PARI) for(q=2, 2048, if(isprimepower(q), m=q^2+q+1; if(isprime(m), print1(m, ", "))))
CROSSREFS
KEYWORD
nonn
AUTHOR
Martin Becker, May 18 2021
STATUS
approved