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%I #20 May 17 2023 13:55:00
%S 0,1,3,5,11,15,17,153,169,273,317,373,923,1403,1969,2349,7809,10313,
%T 12291,24865,41289
%N Integers k such that k*3^k + 2 is prime.
%C Initial corresponding primes are 2, 5, 83 and 1217.
%C How do this sequence and A006552 compare asymptotically?
%e a(3) = 3 because 3^3 * 3 + 2 = 83 is prime.
%t Select[Range[0, 10000], PrimeQ[# 3^# + 2] &] (* _Vincenzo Librandi_, Dec 02 2015 *)
%o (PARI) for(n=0, 1e6, if(ispseudoprime(3^n*n + 2), print1(n, ", ")));
%o (Magma) [n: n in [0..400] | IsPrime(n*3^n+2)]; // _Vincenzo Librandi_, Dec 02 2015
%Y Cf. A006552, A036290, A182373.
%K nonn,hard,more
%O 1,3
%A _Altug Alkan_, Dec 01 2015
%E a(1) = 0 added by _Vincenzo Librandi_, Dec 02 2015
%E a(21) from _Michael S. Branicky_, May 16 2023
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