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 A033521 #12 May 25 2017 14:41:15
%S A033521 1,76,36626,13775700,5392866995,2099687534810,818177759586592,
%T A033521 318778982954630760,124205035822005824254,48393567952045732290238,
%U A033521 18855421270525299234217319,7346573263558160357598269172,2862420221714879808794571247043
%N A033521 Number of matchings in graph C_{9} X P_{n}.
%D A033521 Per Hakan Lundow, "Computation of matching polynomials and the number of 1-factors in polygraphs", Research reports, No 12, 1996, Department of Mathematics, Umea University.
%H A033521 Alois P. Heinz, <a href="/A033521/b033521.txt">Table of n, a(n) for n = 0..200</a>
%H A033521 Per Hakan Lundow, <a href="http://www.theophys.kth.se/~phl/Text/1factors2.ps.gz">Enumeration of matchings in polygraphs</a>, 1998.
%Y A033521 Row 9 of A287428.
%K A033521 nonn
%O A033521 0,2
%A A033521 _Per H. Lundow_