A367560 -id:A367560 - cp's OEIS frontend

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A367561 Numbers k such that k^7*2^k - 1 is a prime.

Original entry on oeis.org

6, 45, 55, 80, 135, 187, 205, 384, 405, 1291, 1364, 2301, 2486, 2844, 16892, 27308, 30152, 32535, 45324, 71522, 72865

Offset: 1

Juri-Stepan Gerasimov, Nov 22 2023

No further terms <= 100000. - Michael S. Branicky, Aug 28 2024

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), this sequence (m = 7).

[k: k in [1..4000] | IsPrime(k^7*2^k-1)];

Select[Range[3000], PrimeQ[#^7*2^# - 1] &] (* Amiram Eldar, Nov 23 2023 *)

a(16)-a(21) from Michael S. Branicky, Nov 23 2023

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