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.
%I A059803 #21 Jun 13 2017 16:39:39 %S A059803 2,7,29,31,67,149,401,2531,19913,30773,53857,170099 %N A059803 Numbers n such that 9^n - 8^n is prime or a strong pseudoprime. %C A059803 Some of the larger entries may only correspond to probable primes. %C A059803 In general, for any positive integers n, a and b, a>b, a necessary condition for a^n-b^n to be prime is that either a-b=1 and n be a prime or n=1 and a-b be prime (from Arturo Magidin and Hagman in Sci.Math, Sep 11, 2010). - _Vincenzo Librandi_, Sep 12 2010 %o A059803 (PARI) is(n)=ispseudoprime(9^n-8^n) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A059803 Cf. A000043, A057468, A059801, A059802, A062572-A062574, A062576-A062666. %K A059803 nonn,hard %O A059803 1,1 %A A059803 _Mike Oakes_, Feb 23 2001 %E A059803 Three more terms found by Jean-Louis Charton in 2004-2005: a(9) = 30773, a(10) = 53857, a(11) = 170099. - _Alexander Adamchuk_, Dec 08 2006