A023279 -id:A023279 - cp's OEIS frontend

A023309 Primes that remain prime through 4 iterations of function f(x) = 3x + 8.

3181, 9551, 22051, 30941, 32621, 61981, 76651, 99961, 134291, 151901, 163661, 185951, 226691, 227671, 240551, 288191, 342821, 374501, 394411, 402881, 423781, 426301, 446461, 456151, 459091, 460951, 554011, 572321, 577601, 617191, 653831

Offset: 1

David W. Wilson

nonn

Primes p such that 3*p+8, 9*p+32, 27*p+104 and 81*p+320 are also primes. - Vincenzo Librandi, Aug 04 2010

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

Subsequence of A023210, A023248, and A023279.

[n: n in [1..1000000] | IsPrime(n) and IsPrime(3*n+8) and IsPrime(9*n+32) and IsPrime(27*n+104) and IsPrime(81*n+320)]; // Vincenzo Librandi, Aug 04 2010

okQ[n_]:=And@@PrimeQ/@Rest[NestList[3#+8&,n,4]]; Select[Prime[Range[60000]],okQ] (* Harvey P. Dale, Aug 16 2010 *)

a(n) == 1 or 31 (mod 70). - John Cerkan, Oct 04 2016

A023337 Primes that remain prime through 5 iterations of function f(x) = 3x + 8.

Original entry on oeis.org

3181, 61981, 134291, 342821, 459091, 882451, 984931, 1016011, 1028471, 1181701, 1391561, 1897801, 2009311, 2272301, 2476421, 2769791, 3048041, 3085421, 3128821, 3207221, 3545111, 4092931, 4690591, 5015321, 5863651, 6027941, 6361351, 6796541

Offset: 1

David W. Wilson

nonn

Primes p such that 3*p+8, 9*p+32, 27*p+104, 81*p+320, and 243*p+968 are also primes. - Vincenzo Librandi, Aug 05 2010

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

Subsequence of A023210, A023248, A023279, and A023309.

[n: n in [1..25000000] | IsPrime(n) and IsPrime(3*n+8) and IsPrime(9*n+32) and IsPrime(27*n+104) and IsPrime(81*n+320) and IsPrime(243*n+968)] // Vincenzo Librandi, Aug 05 2010

Select[Prime[Range[500000]],And@@PrimeQ[Rest[NestList[3#+8&,#,5]]]&] (* Harvey P. Dale, Apr 07 2014 *)

is(n)=isprime(n) && isprime(3*n+8) && isprime(9*n+32) && isprime(27*n+104) && isprime(81*n+320) && isprime(243*n+968) \\ Charles R Greathouse IV, Oct 11 2016

a(n) == 31 (mod 70). - John Cerkan, Oct 11 2016

cp's OEIS Frontend

A023309 Primes that remain prime through 4 iterations of function f(x) = 3x + 8.

Views

Author

Keywords

Comments

Links

Crossrefs

Programs

Magma

Mathematica

Formula