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 A279201 #12 Dec 16 2016 15:25:19 %S A279201 1,2,12,118,1218,14272 %N A279201 Number of Wilf-equivalence classes of square permutations of 2n things that avoid 123. %H A279201 Samuele Giraudo, S. Vialette, <a href="https://arxiv.org/abs/1601.05962">Unshuffling Permutations</a>, arXiv preprint arXiv:1601.05962 [cs.DS], 2016. %Y A279201 Cf. A279200, A279202, A279203. %K A279201 nonn,more %O A279201 0,2 %A A279201 _N. J. A. Sloane_, Dec 15 2016