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 A208574 #8 Dec 27 2023 00:59:01 %S A208574 3,5,11,17,29,41,59,71,101,137,197,269,419,521,809,1031,1607,2081, %T A208574 3119,4127,6197,8219,12377,16451,24917,32801,49169,65537,98321,131111, %U A208574 196661,262151,393299,524351,786551,1048889,1572869,2097257,3145739,4194581,6292007 %N A208574 Union of A208572 and A208573. %Y A208574 Cf. A001359, A208572, A208573. %K A208574 nonn %O A208574 1,1 %A A208574 _Washington Bomfim_, Feb 28 2012