A023293 -id:A023293 - cp's OEIS frontend

A023321 Primes that remain prime through 4 iterations of function f(x) = 8x + 5.

8431, 9721, 24169, 35311, 63577, 74203, 109471, 109891, 140269, 174613, 176599, 182857, 210187, 241561, 270553, 274837, 274909, 276517, 281557, 324763, 326737, 383659, 464089, 474127, 489109, 498403, 540781, 563587, 576943, 582949, 633253

Offset: 1

David W. Wilson

nonn

Primes p such that 8*p+5, 64*p+45, 512*p+365 and 4096*p+2925 are also primes. - Vincenzo Librandi, Aug 04 2010

John Cerkan, Table of n, a(n) for n = 1..10000

Subsequence of A023230, A023262, A023293, and A105133.

[n: n in [1..5000000] | IsPrime(n) and IsPrime(8*n+5) and IsPrime(64*n+45) and IsPrime(512*n+365) and IsPrime(4096*n+2925)] // Vincenzo Librandi, Aug 04 2010

a(n) == 19 or 31 (mod 42). - John Cerkan, Oct 08 2016

A023349 Primes that remain prime through 5 iterations of function f(x) = 8x + 5.

Original entry on oeis.org

109891, 324763, 852367, 3371527, 3557797, 4448701, 4471549, 5304661, 5616679, 5688919, 5727349, 7766659, 8028109, 8554999, 9034723, 10867099, 11146987, 12396487, 12926401, 14186611, 18274513, 19251517, 20882713, 21810493, 23953921

Offset: 1

David W. Wilson

nonn

Primes p such that 8*p+5, 64*p+45, 512*p+365, 4096*p+2925 and 32768*p+23405 are also primes. - Vincenzo Librandi, Aug 05 2010

John Cerkan, Table of n, a(n) for n = 1..10000

Subsequence of A023230, A023262, A023293, A023321, and A105133.

[n: n in [1..19000000] | IsPrime(n) and IsPrime(8*n+5) and IsPrime(64*n+45) and IsPrime(512*n+365) and IsPrime(4096*n+2925) and IsPrime(32768*n+23405)] // Vincenzo Librandi, Aug 05 2010

p5Q[n_]:=And@@PrimeQ/@NestList[8#+5&,n,5]; Parallelize[Select[Prime[Range[1510000]],p5Q]] (* Harvey P. Dale, Feb 22 2011 *)

a(n) == 19 (mod 42). - John Cerkan, Nov 06 2016

cp's OEIS Frontend

A023321 Primes that remain prime through 4 iterations of function f(x) = 8x + 5.

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