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 A028482 #14 Apr 17 2020 23:05:25 %S A028482 1,199,97021,53924597,30946370401,17931360207872,10421993545062683, %T A028482 6063482153051471479,3528867741726076542167,2053975467997173931810469, %U A028482 1195557391003219846631664779,695906086927354589354168761123,405072252620898699232642344701021 %N A028482 Number of perfect matchings in graph C_{11} X P_{2n}. %D A028482 Per Hakan Lundow, "Computation of matching polynomials and the number of 1-factors in polygraphs", Research report, No 12, 1996, Department of Math., Umea University, Sweden. %H A028482 Alois P. Heinz, <a href="/A028482/b028482.txt">Table of n, a(n) for n = 0..200</a> %H A028482 Alois P. Heinz, <a href="/A028482/a028482.txt">G.f. for A028482</a> %H A028482 Per Hakan Lundow, <a href="http://www.theophys.kth.se/~phl/Text/1factors2.ps.gz">Enumeration of matchings in polygraphs</a>, 1998. %F A028482 G.f.: see link above. %F A028482 a(n) = 2^n * sqrt(Resultant(U_{2*n}(x/2), T_{11}(i*x/2))), where T_n(x) is a Chebyshev polynomial of the first kind, U_n(x) is a Chebyshev polynomial of the second kind and i = sqrt(-1). - _Seiichi Manyama_, Apr 17 2020 %o A028482 (PARI) {a(n) = sqrtint(4^n*polresultant(polchebyshev(2*n, 2, x/2), polchebyshev(11, 1, I*x/2)))} \\ _Seiichi Manyama_, Apr 17 2020 %K A028482 nonn %O A028482 0,2 %A A028482 _Per H. Lundow_