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 A216668 #17 Feb 02 2023 04:19:31 %S A216668 2,2,2,296,296,369719,457578,43410300320,43410300320,43410300320, %T A216668 288975248496 %N A216668 Smallest integer b > 1 such that for all primes p <= prime(n), (b+1)^p - b^p is prime if and only if 2^p-1 is prime. %Y A216668 Cf. A216666. %K A216668 nonn,hard,more %O A216668 1,1 %A A216668 _Jean-Louis Charton_, Sep 13 2012 %E A216668 a(11) from _Jean-Louis Charton_, Oct 03 2012