A070325 Numbers n such that n+1, n^2+1 and n^4+1 are primes.

1, 2, 4, 6, 16, 180, 210, 430, 466, 556, 690, 760, 936, 966, 1150, 1870, 2266, 2646, 2676, 3390, 3516, 3910, 4006, 4566, 4590, 4936, 5086, 6576, 6970, 8626, 9276, 9336, 10006, 13686, 15510, 17320, 17550, 17850, 18040, 18060, 18586, 18700, 19380

Offset

1,2

Links

Charles R Greathouse IV, Table of n, a(n) for n = 1..10000

Mathematica

Do[ If[ PrimeQ[n + 1] && PrimeQ[n^2 + 1] && PrimeQ[n^4 + 1], Print[n]], {n, 1, 20000}]
Select[Prime[Range[2200]]-1, And@@PrimeQ[{#^2+1, #^4+1}]&] (* Harvey P. Dale, Sep 24 2011 *)

Prog

(PARI) for(n=1, 33000, if(isprime(n^2+1)*isprime(n^4+1)*isprime(n+1)==1, print1(n, ", ")))

Crossrefs

Subsequence of A070689. [Zak Seidov, Apr 09 2011]

Sequence in context: A261864 A071243 A112086 * A199578 A367127 A294920

Adjacent sequences: A070322 A070323 A070324 * A070326 A070327 A070328

Keyword

easy,nonn

Author

Benoit Cloitre, May 11 2002

Status

approved