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%I #12 May 22 2023 02:48:44
%S 5,7,19,23,87,107,255,1539,2387,4457,5623,15761,22735,27241,86447
%N Numbers k such that 2^k - 3*k is prime.
%C a(15) > 28500. - _Jinyuan Wang_, Feb 03 2020
%t Do[ If[ PrimeQ[2^n - 3n], Print[n]], {n, 1, 15000, 2}]
%o (PARI) is(k) = ispseudoprime(2^k-3*k); \\ _Jinyuan Wang_, Feb 03 2020
%Y Cf. A093988 (2^k + 3*k is prime).
%K nonn,more
%O 1,1
%A _Robert G. Wilson v_, May 26 2004
%E a(12)-a(14) from _Jinyuan Wang_, Feb 03 2020
%E a(15) from _Michael S. Branicky_, May 21 2023
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