A023324 Primes that remain prime through 4 iterations of function f(x) = 9x + 2.

103, 283, 313, 929, 2549, 2593, 3931, 4091, 5279, 6781, 7759, 8363, 16229, 16493, 16703, 19961, 24071, 25733, 27059, 32191, 34961, 35381, 36341, 44131, 50093, 52973, 59671, 66179, 69833, 69931, 75853, 90031, 92993, 93371, 101879, 103561, 106949

Offset: 1

Author

David W. Wilson

Keywords

• nonn

Comments

Primes p such that 9*p+2, 81*p+20, 729*p+182 and 6561*p+1640 are also primes. - Vincenzo Librandi, Aug 04 2010

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Programs

Magma

[n: n in [1..5000000] | IsPrime(n) and IsPrime(9*n+2) and IsPrime(81*n+20) and IsPrime(729*n+182) and IsPrime(6561*n+1640)] // Vincenzo Librandi, Aug 04 2010

Mathematica

Select[Prime[Range[11000]],AllTrue[Rest[NestList[9#+2&,#,4]],PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Feb 12 2015 *)