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 A230145 #13 Dec 20 2014 17:15:37
%S A230145 3,75,595,333795,25638459,5788790007,898772045457,1467030741832227,
%T A230145 126774706022852173,244108884436744360605,94974266622893811200463,
%U A230145 176151264858556860995936775,95962705639251788100721754775,121363236202656183485569513082175
%N A230145 Denominator of 1/v_n(1/2), where polynomial v_n(x) is used to approximate x->sin(Pi*x)/Pi.
%C A230145 Coefficients of v_n are given by the n-th row of A144859/A144860.
%H A230145 Alois P. Heinz, <a href="/A230145/b230145.txt">Table of n, a(n) for n = 1..99</a>
%p A230145 v:= proc(n) option remember; local f, i, x; f:= unapply(simplify(sum('cat(a||(2*i+1)) *x^(2*i+1)', 'i'=0..n) ), x); unapply(subs(solve({f(1)=0, `if`(n=0, NULL, D(f)(0)=1), seq((D@@i)(f)(1)=-(D@@i)(f)(0), i=2..n)}, {seq(cat(a||(2*i+1)), i=0..n)}), sum('cat(a||(2*i+1)) *x^(2*i+1)', 'i'=0..n) ), x) end: seq(denom(1/v(n)(1/2)), n=1..15);
%t A230145 v[n_] := v[n] = Module[{f, i, x, a}, f[x_] := Sum[a[2*i+1]*x^(2*i+1), {i, 0, n}]; Function[x, Sum[a[2*i+1]*x^(2*i+1), {i, 0, n}] /. First @ Solve[Join[{f[1] == 0}, {If[n == 0, True, f'[0] == 1]}, Table[Derivative[i][f][1] == -Derivative[i][f][0], {i, 2, n}]]]]]; Table[Denominator[1/v[n][1/2]], {n, 1, 15}] (* _Jean-François Alcover_, Feb 13 2014, after Maple *)
%Y A230145 Numerators are given in A230144.
%Y A230145 Cf. A000796.
%K A230145 nonn,frac
%O A230145 1,1
%A A230145 _Alois P. Heinz_, Oct 10 2013