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A267030
Primes p such that p*(3^p) + 2 is also prime.
0
3, 5, 11, 17, 317, 373, 10313
OFFSET
1,1
COMMENTS
The terms of this sequence are the prime terms of A265121.
The first few corresponding primes are 83, 1217, 1948619, 2195382773, ... .
a(8) > 10^5. - Michael S. Branicky, Oct 08 2024
EXAMPLE
p = 17; [17 * (3 ^ 17) + 2] = 2195382773 (is a prime number).
MAPLE
select(p -> isprime(p) and isprime(p*3^p+2), [seq(i, i=3..2000, 2)]); # Robert Israel, Jan 10 2016
MATHEMATICA
Select[Prime@ Range@ 1000, PrimeQ[# (3^#) + 2] &] (* Michael De Vlieger, Jan 09 2016 *)
PROG
(Magma) [p: p in PrimesUpTo(1000) | IsPrime((p*(3^p)+2))]; // Vincenzo Librandi, Jan 10 2016
(PARI) lista(nn) = forprime(p=2, nn, if(ispseudoprime((p*(3^p) + 2)), print1(p, ", "))); \\ Altug Alkan, Jan 10 2016
CROSSREFS
Cf. A265121.
Sequence in context: A090952 A347078 A270778 * A128949 A070316 A298121
KEYWORD
nonn,more
AUTHOR
Emre APARI, Jan 09 2016
STATUS
approved