A112043 Numbers k such that 1*k + 1, 3*k + 1, 9*k + 1, 27*k + 1, 81*k + 1, 243*k + 1 are all primes.

1171240, 1197630, 2023140, 3592890, 4132590, 4151910, 4254250, 4484760, 5167050, 5486110, 7121590, 7279930, 12524820, 13527640, 13595470, 15998640, 17211040, 17269000, 18570370, 20040300, 20402760, 21135310, 21735420

Offset

1,1

Links

Table of n, a(n) for n=1..23.

Mathematica

Select[Range[22*10^6], AllTrue[3^Range[0, 5] #+1, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Sep 08 2019 *)

Prog

(Magma) [n: n in [1..50000000] |IsPrime(n+1) and IsPrime(3*n+1) and IsPrime(9*n+1) and IsPrime(27*n+1)and IsPrime(81*n+1)and IsPrime(243*n+1)] // Vincenzo Librandi, Nov 13 2010

Crossrefs

Cf. A112041, A112042.

Sequence in context: A322690 A322680 A288077 * A114677 A172591 A250962

Adjacent sequences: A112040 A112041 A112042 * A112044 A112045 A112046

Keyword

nonn

Author

Pierre CAMI, Aug 26 2005

Status

approved