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This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A062574 Numbers k such that 8^k - 7^k is prime or a strong pseudoprime.

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%I A062574 #29 Jul 04 2021 07:52:16
%S A062574 7,11,17,29,31,79,113,131,139,4357,44029,76213,83663,173687,336419,
%T A062574 615997
%N A062574 Numbers k such that 8^k - 7^k is prime or a strong pseudoprime.
%C A062574 All terms are prime. - _Alexander Adamchuk_, Apr 27 2008
%H A062574 Henri & Renaud Lifchitz, <a href="http://www.primenumbers.net/prptop/searchform.php?form=8%5Ex-7%5Ex&amp;action=Search">PRP Records</a>.
%t A062574 Select[Range[200], PrimeQ[8^# - 7^#] &] (* _Vladimir Joseph Stephan Orlovsky_, Feb 22 2012 *)
%o A062574 (PARI) is(n)=ispseudoprime(8^n-7^n) \\ _Charles R Greathouse IV_, Sep 04 2013
%Y A062574 Cf. A000043, A057468, A059801, A059802, A059803 (9^n-8^n is prime), A062572-A062666.
%Y A062574 Cf. A016177 = 8^n - 7^n.
%K A062574 nonn,hard
%O A062574 1,1
%A A062574 _Mike Oakes_, May 18 2001, May 19 2001
%E A062574 Two more terms 44029 and 76213 found by Ananda Tallur & _Jean-Louis Charton_ in 2003.
%E A062574 Three more terms 83663, 173687 and 336419 found by _Jean-Louis Charton_ in 2004 and 2008
%E A062574 New term 615997 found by Jean-Louis Charton corresponding to a probable prime with 556301 digits. _Jean-Louis Charton_, Sep 02 2009