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 A028448 #14 Dec 19 2013 05:49:47
%S A028448 1,5,121,1845,32000,535229,9049169,152526845,2573281769,43402320448,
%T A028448 732106008249,12348802743437,208295014563521,3513435627771565,
%U A028448 59263242055245056,999628735946792581,16861339891166667849,284410369641222811445,4797320930581855672689
%N A028448 Number of perfect matchings in graph P_{2} X P_{4} X P_{n}.
%H A028448 Alois P. Heinz, <a href="/A028448/b028448.txt">Table of n, a(n) for n = 0..800</a>
%H A028448 Per Hakan Lundow, <a href="http://www.theophys.kth.se/~phl/Text/1factors.pdf">Computation of matching polynomials and the number of 1-factors in polygraphs</a>, Research report, No 12, 1996, Department of Math., Umea University, Sweden.
%H A028448 Per Hakan Lundow, <a href="http://www.theophys.kth.se/~phl/Text/1factors2.ps.gz">Enumeration of matchings in polygraphs</a>, 1998.
%F A028448 G.f.: (-x^19 +17*x^18 -53*x^17 -383*x^16 +2051*x^15 +1155*x^14 -16891*x^13 +9523*x^12 +45157*x^11 -41065*x^10 -41065*x^9 +45157*x^8 +9523*x^7 -16891*x^6 +1155*x^5 +2051*x^4 -383*x^3 -53*x^2 +17*x -1) / (x^21 -22*x^20 +42*x^19 +990*x^18 -3493*x^17 -12199*x^16 +55858*x^15 +27106*x^14 -289337*x^13 +146481*x^12 +488514*x^11 -488514*x^10 -146481*x^9 +289337*x^8 -27106*x^7 -55858*x^6 +12199*x^5 +3493*x^4 -990*x^3 -42*x^2 +22*x -1). - _Alois P. Heinz_, Dec 08 2013
%Y A028448 Column k=4 of A181206.
%K A028448 nonn
%O A028448 0,2
%A A028448 _Per H. Lundow_