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%I #19 Nov 01 2018 21:30:48
%S 3,13,71,14533,26641,48179
%N Numbers k such that 18^k - 17^k is prime, or a strong pseudoprime.
%C Terms < 10000 found by Mike Oakes.
%C Term 14533 found by Lelio R Paula in June 2008 corresponding to a probable prime with 18243 digits.
%C Terms 26641 and 48179 found by Jean-Louis Charton in December 2010 corresponding to probable primes with 33442 and 60478 digits.
%C a(7) > 10^5. - _Robert Price_, Nov 30 2012
%H <a href="http://www.primenumbers.net/prptop/searchform.php?form=18%5Ep-17%5Ep">Top probable primes of the form 18^p-17^p</a>
%o (PARI) is(n)=ispseudoprime(18^n-17^n) \\ _Charles R Greathouse IV_, Jun 06 2017
%Y Cf. A000043, A057468, A059801, A059802, A059803, A062572-A062583, A062585-A062666.
%K nonn,hard
%O 1,1
%A _Jean-Louis Charton_, Mar 19 2011
%E Edited by _M. F. Hasler_, Sep 21 2013