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 A335326 #10 Jul 31 2022 07:46:19
%S A335326 4369,13741,31609,6973057,208969201
%N A335326 Lesser of 2 consecutive Fermat pseudoprimes to base 2 with no prime numbers in between them.
%C A335326 The corresponding larger counterparts are 4371, 13747, 31621, 6973063, 208969223.
%C A335326 The corresponding gaps between the consecutive pseudoprimes are 2, 6, 12, 6, 22.
%C A335326 a(6) > 10^15, if it exists.
%e A335326 4369 is a term since it is a Fermat pseudoprime to base 2, and between it and the next Fermat pseudoprime to base 2, 4371, there is only one number, 4370, which is composite.
%t A335326 psp = Cases[Import["https://oeis.org/A001567/b001567.txt", "Table"], {_, _}][[;; , 2]]; s = {}; Do[If[NextPrime[psp[[k]]] > psp[[k + 1]], AppendTo[s, psp[[k]]]], {k, 1, Length[psp] - 1}]; s
%Y A335326 Cf. A001567, A173619, A175736, A175737, A175738.
%K A335326 nonn,hard,more
%O A335326 1,1
%A A335326 _Amiram Eldar_, Jun 01 2020