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

Author

Zak Seidov, Apr 09 2011

Keywords

• nonn

Comments

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

Examples

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

Programs

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

Extensions

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