A127871 Numbers n such that n^4+1 and n^4+3 are twin primes.

2, 16, 28, 34, 82, 118, 266, 296, 328, 436, 778, 1126, 1238, 1280, 1486, 1496, 1612, 1952, 2102, 2192, 2312, 2414, 2578, 2690, 2770, 2834, 2872, 3100, 3410, 3550, 3620, 3752, 4012, 4016, 4240, 4264, 4450, 4772, 5084, 5458, 5732, 5798, 5864, 6704, 7208

Offset: 1

Author

Zak Seidov, Apr 05 2007

Keywords

• nonn

Comments

Intersection of A000068 and A125259.

Smallest k such that a(k+1) = a(k) + 2 is 364. - Altug Alkan, May 15 2018

Links

• Robert Israel, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000068, A125259.

Programs

Maple

select(t -> isprime(t^4+1) and isprime(t^4+3), [seq(i,i=2..10^4,2)]); # Robert Israel, May 14 2018

Mathematica

Select[Range[0,200000,2],PrimeQ[ #^4+1]&&PrimeQ[ #^4+3]&]
Select[Range[7300],AllTrue[#^4+{1,3},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Sep 18 2019 *)

PARI

isok(n) = isprime(n^4+1) && isprime(n^4+3); \\ Michel Marcus, May 15 2018