A367572 Numbers k such that k^8*2^k - 1 is a prime.

5, 7, 49, 165, 251, 345, 385, 945, 949, 1001, 1963, 2113, 2249, 3751, 4381, 4911, 5133, 10039, 29693, 34901, 73885, 99319, 104883, 113613

Offset: 1

Author

Juri-Stepan Gerasimov, Nov 23 2023

Keywords

• nonn
• more

Crossrefs

Numbers k such that k^m*2^k - 1 is a prime: A000043 (m = 0), A002234 (m = 1), A058781 (m = 2), A367037 (m = 3), A367102 (m = 4), A367464 (m = 5), A367478 (m = 6), A367561 (m = 7), this sequence (m = 8).

Programs

Magma

[k: k in [1..4000] | IsPrime(k^8*2^k-1)];

Mathematica

Select[Range[5000], PrimeQ[#^8*2^# - 1] &] (* Amiram Eldar, Nov 23 2023 *)

Extensions

a(19)-a(20) from Michael S. Branicky, Nov 23 2023

a(21) from Michael S. Branicky, Nov 25 2023

a(22)-a(24) from Michael S. Branicky, Aug 29 2024