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 A191177 #11 Aug 08 2025 04:29:01 %S A191177 1,3,9,21,27,33,75,81,99,105,129,183,237,243,291,297,315,321,387,393, %T A191177 417,513,669,723,729,885,891,939,945,963,969,1155,1161,1179,1185,1251, %U A191177 1257,1281 %N A191177 Integers in (3+A191126)/4; contains A191126 as a proper subsequence. %C A191177 See A191126. %t A191177 (* See A191126. *) %Y A191177 Cf. A191126, A191113. %K A191177 nonn,more %O A191177 1,2 %A A191177 _Clark Kimberling_, May 27 2011