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 A365640 #63 Nov 16 2023 05:56:52
%S A365640 2,3,5,9,17,257,65537
%N A365640 Prime powers of the form 2^k + 1.
%C A365640 By Mihăilescu's theorem, this is just the union of {2, 9} and the Fermat primes A019434. - _Robert Israel_, Nov 10 2023
%o A365640 (Magma) [2^k+1: k in [0..1000] | IsPrimePower(2^k+1)];
%Y A365640 Subsequence of A000961. Supersequence of A019434 and A092506.
%K A365640 nonn
%O A365640 1,1
%A A365640 _Juri-Stepan Gerasimov_, Nov 10 2023