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%I #14 Jun 06 2021 19:23:23
%S 0,11,39,323,12415,14655,27679
%N Numbers k such that 23^k + 2 is prime.
%C No further terms < 100000. - _Ray Chandler_, Aug 03 2011
%H Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=23%5En%2B2&action=Search">PRP Records</a>.
%t Do[ f = 23^n + 2; If[ PrimeQ[ f ], Print[ {n, f} ] ], {n, 1, 323} ]
%o (PARI) is(n)=ispseudoprime(23^n+2) \\ _Charles R Greathouse IV_, Feb 17 2017
%Y Cf. A051783 (k such that 3^k + 2 is prime).
%Y Cf. A087885 (k such that 5^k + 2 is prime).
%Y Cf. A090649, A109076, A113480, A138048, A138049, A138051, A087886, A113481.
%K nonn,more
%O 1,2
%A _Alexander Adamchuk_, Mar 02 2008
%E a(5)-a(7) from _Ray Chandler_, Aug 01 2011
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