A023278 -id:A023278 - cp's OEIS frontend

A023308 Primes that remain prime through 4 iterations of the function f(x) = 3x + 4.

3203, 21683, 34613, 52813, 103843, 116933, 117443, 165443, 172933, 193603, 195053, 213973, 226783, 321053, 322193, 357613, 360323, 362233, 363403, 368743, 472393, 474143, 496333, 518543, 528673, 569083, 571303, 631853, 654623, 714893, 758503

Offset: 1

David W. Wilson

nonn

Primes p such that 3*p+4, 9*p+16, 27*p+52 and 81*p+160 are also primes. - Vincenzo Librandi, Aug 04 2010

All a(n) == 33 or 53 (mod 70). - John Cerkan, Oct 04 2016

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

Subsequence of A023209, A023247, A023278, and A034936.

Filtered([1..760000],n->IsPrime(n) and IsPrime(3*n+4) and IsPrime(9*n+16) and IsPrime(27*n+52) and IsPrime(81*n+160)); # Muniru A Asiru, Dec 07 2018

[n: n in [1..1000000] | IsPrime(n) and IsPrime(3*n+4) and IsPrime(9*n+16) and IsPrime(27*n+52) and IsPrime(81*n+160)] // Vincenzo Librandi, Aug 04 2010

select(n->isprime(n) and isprime(3*n+4) and isprime(9*n+16) and isprime(27*n+52) and isprime(81*n+160),[$1..760000]); # Muniru A Asiru, Dec 07 2018

Select[Prime[Range[10000]], Union[PrimeQ[NestList[(3# + 4 &), #, 4]]] == {True} &] (* Alonso del Arte, Nov 30 2018 *)

is(n) = my(x=3*n+4, i=0); while(1, if(!ispseudoprime(x), return(0), i++); if(i==4, return(1)); x=3*x+4)
forprime(p=1, 760000, if(is(p), print1(p, ", "))) \\ Felix Fröhlich, Dec 07 2018

A023336 Primes that remain prime through 5 iterations of function f(x) = 3x + 4.

Original entry on oeis.org

34613, 165443, 321053, 363403, 474143, 496333, 528673, 631853, 834503, 957563, 1199623, 1274803, 1817093, 1918733, 2063423, 2611663, 2889703, 3224233, 3652703, 3697433, 3824413, 3852973, 4655873, 4708793, 5089943, 5508263, 5937853, 6067073

Offset: 1

David W. Wilson

nonn

Primes p such that 3*p+4, 9*p+16, 27*p+52, 81*p+160 and 243*p+484 are also primes. - Vincenzo Librandi, Aug 05 2010

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

Subsequence of A023209, A023247, A023278, A023308, and A034936.

[n: n in [1..25000000] | IsPrime(n) and IsPrime(3*n+4) and IsPrime(9*n+16) and IsPrime(27*n+52) and IsPrime(81*n+160) and IsPrime(243*n+484)] // Vincenzo Librandi, Aug 05 2010

a(n) == 33 (mod 70). - John Cerkan, Oct 10 2016

cp's OEIS Frontend

A023308 Primes that remain prime through 4 iterations of the function f(x) = 3x + 4.

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