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Numbers k such that 3^k*k^3 - 2 is a prime.
1

%I #24 Aug 25 2024 12:54:38

%S 3,15,23,53,79,1767,2325,2553,8355,12707,13377,17265,30165,45807,

%T 65773,98981

%N Numbers k such that 3^k*k^3 - 2 is a prime.

%t Select[Range[3000], PrimeQ[3^#*#^3 - 2] &] (* _Amiram Eldar_, Oct 30 2023 *)

%o (Magma) [k: k in [1..500] | IsPrime(3^k*k^3-2)];

%Y Cf. A058780, A058781.

%K nonn,more

%O 1,1

%A _Juri-Stepan Gerasimov_, Oct 30 2023

%E a(10)-a(12) from _Amiram Eldar_, Oct 30 2023

%E a(13)-a(14) from _Hugo Pfoertner_, Oct 31 2023

%E a(15) from _Michael S. Branicky_, Nov 04 2023

%E a(16) from _Michael S. Branicky_, Aug 25 2024