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%I #24 Feb 23 2024 13:41:43
%S 0,1,2,3,4,10,11,17,20,28,41,48,57,58,59,71,208,972,993,1432,2001,
%T 2175,2622,3419,3720,4860,7300,7402,14988,15774,18510,22872,52139,
%U 77028,149025,172170,239699
%N Numbers n such that 2*6^n+1 is prime.
%C If 6^n is of the form T(x,y) = 2xy+x+y [A083487] then 2*6^n+1 is not prime. - _Vincenzo Librandi_, Nov 13 2010
%C a(1)-a(37) proven prime by the primality proving program LLR. - _Robert Price_, Jan 08 2016
%C a(38) > 2.5*10^5. - _Robert Price_, Jan 08 2016
%t Select[Range[0, 2000], PrimeQ[2*6^# + 1] &] (* _Vladimir Joseph Stephan Orlovsky_, Jan 31 2012 *)
%o (PARI) isok(n) = isprime(2*6^n+1); \\ _Michel Marcus_, Jan 08 2016
%Y Cf. A057472, A120024, A205771.
%K nonn
%O 1,3
%A _Pierre CAMI_, Jun 04 2006
%E More terms from _Pierre CAMI_, Jun 16 2006
%E a(32)-a(37) from _Robert Price_, Jan 08 2016
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