A070157 n-1, n+1, 1+n^2, 1+n^4 and 1+n^8 are all prime numbers.

4, 19380, 9443670, 11054760, 15992070, 22482330, 32557380, 51102510, 57978840, 60549240, 64671570, 84045960, 89757960, 111316170, 112821690, 116433510, 171124380, 171418650, 183082350, 196694760, 197021160, 241803240, 266498460

Offset

1,1

Links

Table of n, a(n) for n=1..23.

Example

3, 5, 17, 257, 65537 are the Fermat primes; 19379, 19381, 375584401, 141063641523360001 and 19898950959831015581425689600000001 are primes.

Mathematica

Do[p = Prime[n] + 1; If[ PrimeQ[p + 1] && PrimeQ[1 + p^2] && PrimeQ[1 + p^4] && PrimeQ[1 + p^8], Print[p]], {n, 1, 115000000}]
Select[Range[2665*10^5], AllTrue[{#-1, #+1, #^2+1, #^4+1, #^8+1}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Nov 03 2019 *)

Crossrefs

Cf. A070155, A070156.

Sequence in context: A162703 A258101 A265215 * A003556 A331667 A053015

Adjacent sequences: A070154 A070155 A070156 * A070158 A070159 A070160

Keyword

nonn

Author

Labos Elemer, Apr 23 2002

Extensions

Edited and extended by Robert G. Wilson v, May 04 2002

Status

approved