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Numbers k such that (6^k)*(2^k - 1) + 1 is prime.
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%I #16 Apr 23 2023 02:20:04

%S 1,2,4,8,15,46,58,74,262,898,13110,20256,21632

%N Numbers k such that (6^k)*(2^k - 1) + 1 is prime.

%C a(11) > 11200. - _Jinyuan Wang_, Mar 19 2020

%o (PARI) is(n)=ispseudoprime((6^n)*(2^n-1)+1) \\ _Charles R Greathouse IV_, Jun 13 2017

%o (Magma) [k: k in [1..300] | IsPrime((6^k)*(2^k-1)+1)]; // _Jinyuan Wang_, Mar 19 2020

%Y Cf. A098863 ((6^k)*(2^k - 1) - 1 is prime).

%K nonn,more

%O 1,2

%A _Pierre CAMI_, Oct 12 2004

%E a(11)-a(13) from _Michael S. Branicky_, Apr 22 2023