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 A000450 M4709 N2012 #23 Aug 10 2017 18:21:32
%S A000450 1,10,50,385,3130,28764,291900,3249210,39367395,515874470,7270929806,
%T A000450 109691447395,1763782644020,30114243100760,544123405603800,
%U A000450 10373304279494964,208092476689208805,4381794437494059810,96635643877147885450,2227562535558247510885
%N A000450 Coefficients of ménage hit polynomials.
%D A000450 J. Riordan, An Introduction to Combinatorial Analysis, Wiley, 1958, p. 198.
%D A000450 N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
%D A000450 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A000450 R. C. Read, <a href="/A000684/a000684_1.pdf">Letter to N. J. A. Sloane, Oct. 29, 1976</a>
%t A000450 max = 23; f[x_, y_] := Sum[n!*((x*y)^n/(1 + x*(y-1))^(2*n+1)), {n, 0, max} ]; t = MapIndexed[Take[#1, #2[[1]]]&, CoefficientList[Series[f[x, y], {x, 0, max}, {y, 0, max}], {x, y}]]; a[n_] := t[[n+1, n-3]]; Table[a[n], {n, 4, max}] (* _Jean-François Alcover_, Feb 08 2016, after _Vladeta Jovovic_ in A058057 *)
%Y A000450 A diagonal of A058057.
%K A000450 nonn
%O A000450 4,2
%A A000450 _N. J. A. Sloane_, _Simon Plouffe_