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A127871 Numbers n such that n^4+1 and n^4+3 are twin primes. 4
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

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

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 *)

PROG

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

CROSSREFS

Cf. A000068, A125259.

Sequence in context: A067555 A108705 A113933 * A242933 A321308 A109210

Adjacent sequences:  A127868 A127869 A127870 * A127872 A127873 A127874

KEYWORD

nonn

AUTHOR

Zak Seidov, Apr 05 2007

STATUS

approved

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Last modified June 17 17:32 EDT 2021. Contains 345085 sequences. (Running on oeis4.)