login
Primes that remain prime through 5 iterations of function f(x) = 4x + 9.
1

%I #21 Sep 08 2022 08:44:47

%S 18257,19541,22063,48383,73037,73133,78173,88261,93811,101051,104537,

%T 152377,153941,162343,168043,175523,204251,211681,238463,287341,

%U 375253,386713,423961,659513,672181,676103,688027,741283,759491,770951,786673

%N Primes that remain prime through 5 iterations of function f(x) = 4x + 9.

%C Primes p such that 4*p+9, 16*p+45, 64*p+189, 256*p+765 and 1024*p+3069 are also primes. - _Vincenzo Librandi_, Aug 05 2010

%H John Cerkan, <a href="/A023340/b023340.txt">Table of n, a(n) for n = 1..10000</a>

%o (Magma) [n: n in [1..10000000] | IsPrime(n) and IsPrime(4*n+9) and IsPrime(16*n+45) and IsPrime(64*n+189) and IsPrime(256*n+765) and IsPrime(1024*n+3069)] // _Vincenzo Librandi_, Aug 05 2010

%o (PARI) is(n)=isprime(n) && isprime(4*n+9) && isprime(16*n+45) && isprime(64*n+189) && isprime(256*n+765) && isprime(1024*n+3069) \\ _Charles R Greathouse IV_, Oct 11 2016

%Y Subsequence of A023216, A023251, A023282, A023312, and A111199.

%K nonn

%O 1,1

%A _David W. Wilson_