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 A058721 #12 Oct 09 2019 02:51:25 %S A058721 1,2,7,49,733,29760,9000402 %N A058721 Number of simple matroids on n labeled points. %H A058721 W. M. B. Dukes, <a href="http://www.stp.dias.ie/~dukes/matroid.html">Tables of matroids</a>. %H A058721 W. M. B. Dukes, <a href="https://web.archive.org/web/20030208144026/http://www.stp.dias.ie/~dukes/phd.html">Counting and Probability in Matroid Theory</a>, Ph.D. Thesis, Trinity College, Dublin, 2000. %H A058721 W. M. B. Dukes, <a href="https://arxiv.org/abs/math/0411557">The number of matroids on a finite set</a>, arXiv:math/0411557 [math.CO], 2004. %H A058721 W. M. B. Dukes, <a href="http://emis.impa.br/EMIS/journals/SLC/wpapers/s51dukes.html">On the number of matroids on a finite set</a>, Séminaire Lotharingien de Combinatoire 51 (2004), Article B51g. %H A058721 <a href="/index/Mat#matroid">Index entries for sequences related to matroids</a> %Y A058721 Row sums of A058720. %K A058721 nonn,nice,more %O A058721 2,2 %A A058721 _N. J. A. Sloane_, Dec 31 2000