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 A062588 #26 Jul 04 2021 07:53:03 %S A062588 2,127,877 %N A062588 Numbers k such that 22^k - 21^k is prime. %C A062588 All terms are prime. %C A062588 No other terms less than 10^5. - _Robert Price_, May 28 2012 %o A062588 (PARI) is(n)=ispseudoprime(22^n-21^n) \\ _Charles R Greathouse IV_, Jun 12 2017 %Y A062588 Cf. A000043, A057468, A059801, A059802, A062572-A062666. %K A062588 nonn,hard,bref,more %O A062588 1,1 %A A062588 _Mike Oakes_, May 18 2001, May 19 2001