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 A062643 #14 Jul 04 2021 09:01:34 %S A062643 19,101,5939 %N A062643 Numbers k such that 77^k - 76^k is prime. %C A062643 Terms > 1000 are often only strong pseudoprimes. %C A062643 a(4) > 10^5. - _Robert Price_, Sep 01 2014 %o A062643 (PARI) is(n)=ispseudoprime(77^n-76^n) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A062643 Cf. A000043, A057468, A059801, A059802, A062572-A062666. %K A062643 nonn,hard,bref %O A062643 1,1 %A A062643 _Mike Oakes_, May 18 2001, May 19 2001