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%I #14 Nov 01 2018 21:32:20
%S 7,13,31,43,269,353,383,619,829,877,4957,5711,8317,21739,24029,38299
%N Numbers k such that (8^k + 7^k)/15 is prime.
%C Terms 21739 and 24029 were found by Lelio R. Paula in February and April 2009. Term 38299 was found by Jean-Louis Charton in October 2010 corresponding to a probable prime with 34587 digits.
%C a(17) > 10^5. - _Robert Price_, Dec 29 2012
%H <a href="http://www.primenumbers.net/prptop/searchform.php?form=%288%5En%2B7%5En%29%2F15&action=Search">Top probable primes of form (8^n+7^n)/15</a>
%o (PARI) is(n)=isprime((8^n+7^n)/15) \\ _Charles R Greathouse IV_, Feb 17 2017
%Y See also A062574.
%K hard,nonn
%O 1,1
%A _Jean-Louis Charton_, Oct 06 2010
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