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 A062635 #18 Jul 04 2021 09:00:14 %S A062635 2,17,1543,83653 %N A062635 Numbers k such that 69^k - 68^k is prime. %C A062635 Terms greater than 1000 are often only strong pseudoprimes. %C A062635 a(5) > 10^5. - _Robert Price_, Dec 16 2013 %o A062635 (PARI) is(n)=ispseudoprime(69^n-68^n) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A062635 Cf. A000043, A057468, A059801, A059802, A062572-A062666. %K A062635 nonn,hard,bref %O A062635 1,1 %A A062635 _Mike Oakes_, May 18 2001, May 19 2001 %E A062635 a(4) from _Robert Price_, Dec 16 2013 (Computer run by Adam Marciniec)