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A308413 Numbers k such that 23^(k+19) + 19^(k+17) + 17^(k+13) + 13^(k+11) + 11^(k+7) + 7^(k+5) + 5^(k+3) + 3^(k+2) - 1 is prime. 0

%I

%S 6,60,66,414,29340

%N Numbers k such that 23^(k+19) + 19^(k+17) + 17^(k+13) + 13^(k+11) + 11^(k+7) + 7^(k+5) + 5^(k+3) + 3^(k+2) - 1 is prime.

%C a(6) > 50000 (if it exists).

%t ParallelTable[If[PrimeQ[23^(n+19) + 19^(n+17) + 17^(n+13) + 13^(n+11) + 11^(n+7) + 7^(n+5) + 5^(n+3) + 3^(n+2) - 1], n, Nothing], {n, 30000}]

%Y Cf. A306573.

%K nonn,hard,more,less

%O 1,1

%A _Mikk Heidemaa_, May 31 2019

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Last modified October 21 09:09 EDT 2020. Contains 337911 sequences. (Running on oeis4.)