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 A013549 #24 Oct 28 2023 08:54:13 %S A013549 1,2,4,10,41,76 %N A013549 Incorrect version of A000085. %C A013549 Appears on page 2, Figure 2 (left column) of the reference; Corollary 1.6 (page 17) says that the permutations counted are involutions. - _Sean A. Irvine_, Aug 08 2018 %H A013549 Frank Schmidt and Rodica Simion, <a href="https://doi.org/10.1007/BF01834201">Card shuffling and a transformation on S_n</a>, Aequationes Math. 44 (1992), no. 1, 11-34. %K A013549 dead %O A013549 1,2