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%I #16 Sep 08 2022 08:46:20
%S 1,3,65,123,435,465,677,947,4215,5615
%N Numbers k such that 3^k + k - 1 is a prime.
%C Next term, if it exists, is greater than 10000.
%C Corresponding primes: 3, 29, 10301051460877537453973547267907, 48519278097689642681155855396759336072749841943521979872949, ...
%p select(k->isprime(3^k+k-1),[$1..1000]); # _Muniru A Asiru_, Apr 05 2018
%t Flatten[{Select[Range[6000], PrimeQ[3^# + # - 1] &]}]
%o (Magma) [k: k in [1..700] | IsPrime(3^k+k-1)];
%o (PARI) lista(nn) = forstep(n=1, nn, 2, if(ispseudoprime(3^n + n - 1), print1(n, ", "))); \\ _Altug Alkan_, Apr 01 2018
%Y Cf. A173063, A301632.
%K nonn,more
%O 1,2
%A _Vincenzo Librandi_, Apr 01 2018
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