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 A062644 #16 Jul 04 2021 09:01:36 %S A062644 7,5749 %N A062644 Numbers k such that 78^k - 77^k is prime. %C A062644 Terms > 1000 are often only strong pseudoprimes. %C A062644 a(3) > 10^5. - _Robert Price_, Oct 04 2014 %o A062644 (PARI) is(n)=ispseudoprime(78^n-77^n) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A062644 Cf. A000043, A057468, A059801, A059802, A062572-A062666. %K A062644 nonn,hard,bref,more %O A062644 1,1 %A A062644 _Mike Oakes_, May 18 2001, May 19 2001