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 A217396 #67 Jun 25 2025 19:05:51 %S A217396 1,2,3,5,7,13 %N A217396 Prime indices of Euler's lucky numbers. %F A217396 a(n) = A000720(A014556(n)). - _Alexander R. Povolotsky_, Sep 22 2022 %K A217396 nonn,fini,full,less %O A217396 1,2 %A A217396 _Raphie Frank_, Oct 02 2012