A267030 Primes p such that p*(3^p) + 2 is also prime.

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, ... .

Links

Table of n, a(n) for n=1..7.

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

Adjacent sequences: A267027 A267028 A267029 * A267031 A267032 A267033

Keyword

nonn,more

Author

Emre APARI, Jan 09 2016

Status

approved