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%I #39 Feb 26 2024 10:08:52
%S 5,41,257,1553,15672832817,121871948002097,4387390128075569,
%T 161656255492952812128627920091307258673,
%U 34917751186477807419783630739722367873841
%N Primes of the form (6^n-11)/5.
%C These primes are also given by sum 6^k -1 with k>0 and are then companions of A165210 which corresponds also to sum 6^k +1 with k>0. (Be careful: there is a shifting between the k and the n values).
%C Corresponding exponents n are in A199165. - _Gilbert Mozzo_, Nov 05 2011
%e (6^4-11)/5=257, which is in the sequence because is prime.
%t lst={}; Do[If[PrimeQ[(6^n-11)/5], Print[(6^n-11)/5]; AppendTo[lst, (6^n-11)/5]], {n, 10^6}];
%o (Magma) [(6^n-11)/5: n in [1..10^3] | IsPrime((6^n-11) div 5)];
%o (PARI) for(n=1,1e4,if(ispseudoprime(t=6^n\5-2),print1(t", "))) \\ _Charles R Greathouse IV_, Nov 01 2011
%Y Cf. A165210, A004062, A199165.
%K nonn
%O 1,1
%A _Gilbert Mozzo_, Oct 29 2011
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