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Numbers k such that 13^k - 12^k is prime.
1

%I #20 Jul 04 2021 07:51:22

%S 17,31,41,47,109,163,643,2459,9743,30271,87557

%N Numbers k such that 13^k - 12^k is prime.

%C Terms greater than 1000 may correspond to (unproven) strong pseudoprimes. [Clarified by _M. F. Hasler_, Sep 16 2013]

%o (PARI) is(n)=ispseudoprime(13^n-12^n) \\ _Charles R Greathouse IV_, Jun 12 2017

%Y Cf. A000043, A057468, A059801, A059802, A062572-A062666.

%K nonn,hard

%O 1,1

%A _Mike Oakes_, May 18 2001, May 19 2001

%E Two more terms 30271 and 87557 (found in 2007 and 2008) from _Jean-Louis Charton_, Sep 02 2009