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 A298670 #14 Sep 08 2021 21:14:38 %S A298670 4,5,6,7,8,11,12,13,14,17,18,20,21,23,25,27,28,29,31,32 %N A298670 Numbers k such that A298669(k)*2^k + 1 is a prime factor of the Fermat number 2^(2^(k-2)) + 1. %Y A298670 Cf. A298669. %K A298670 nonn,more %O A298670 1,1 %A A298670 _Arkadiusz Wesolowski_, Jan 24 2018