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 A062638 #21 Jul 04 2021 09:02:10 %S A062638 61,9883,64693 %N A062638 Numbers k such that 72^k - 71^k is prime. %C A062638 Integers corresponding to n greater than 1000 are often only strong pseudoprimes. %C A062638 a(4) > 10^5. - _Robert Price_, Mar 20 2014 %o A062638 (PARI) is(n)=ispseudoprime(72^n-71^n) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A062638 Cf. A000043, A057468, A059801, A059802, A062572-A062666. %K A062638 nonn,hard,bref %O A062638 1,1 %A A062638 _Mike Oakes_, May 18 2001, May 19 2001 %E A062638 a(3) from _Robert Price_, Mar 20 2014 (computer run by Adam Marciniec)