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%I #15 Mar 25 2018 09:43:31
%S 3,5,15,27
%N Numbers k such that 16*k^k - 1 is prime.
%C All terms are odd since 16*(2*m)^(2*m) - 1 = (2^(m+2)*m^m - 1)*(2^(m+2)*m^m + 1). - _Altug Alkan_, Mar 23 2018
%C Next term, if it exists, is greater than 5000. - _Vaclav Kotesovec_, Mar 25 2018
%t Select[Range[1000], PrimeQ[16*#^# - 1] &] (* _Vaclav Kotesovec_, Mar 25 2018 *)
%o (PARI) for(n=0, 1000, if(isprime(16*n^n-1), print1(n", ")))
%Y Cf. A110931, A301522.
%K nonn,more
%O 1,1
%A _Seiichi Manyama_, Mar 23 2018
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