A188698 Numbers k such that 1+k, 1+k^2, 1+k^4 and 1+k^16 are all prime.

1, 2, 690, 33190, 57106, 77140, 135606, 258990, 303430, 331140, 337536, 359230, 375646, 455526, 458326, 493396, 548226, 550540, 585106, 602056, 659250, 680830, 742306, 800406, 827680, 870240, 918340, 925390, 968320, 1203100, 1273890, 1455526, 1497576, 1605016

Offset

1,2

Comments

Subsequence of A070325, which itself is a subsequence of A070689, which itself is a subsequence of A006093.

Links

Table of n, a(n) for n=1..34.

Example

a(3) = 690 = A070689(32) = A070325(11) = A006093(125).

Prog

(Magma) [n: n in [0..7000000]| IsPrime(1+n) and IsPrime(1+n^2) and IsPrime(1+n^4) and IsPrime(1+n^16)]; // Vincenzo Librandi, Apr 11 2011

Crossrefs

Sequence in context: A079195 A120123 A140014 * A209364 A106301 A127623

Adjacent sequences: A188695 A188696 A188697 * A188699 A188700 A188701

Keyword

nonn

Author

Zak Seidov, Apr 09 2011

Extensions

a(1) = 1 prepended by Vincenzo Librandi, Apr 11 2011

Status

approved