1function A3x = A3coeff(n)
2%A3COEFF  Evaluate coefficients for A_3
3%
4%   A3x = A3COEFF(n) evaluates the coefficients of epsilon^l in Eq. (24).
5%   n is a scalar.  A3x is a 1 x 6 array.
6
7  persistent coeff nA3
8  if isempty(coeff)
9    nA3 = 6;
10    coeff = [ ...
11        -3, 128, ...
12        -2, -3, 64, ...
13        -1, -3, -1, 16, ...
14        3, -1, -2, 8, ...
15        1, -1, 2, ...
16        1, 1, ...
17            ];
18  end
19  A3x = zeros(1, nA3);
20  o = 1;
21  k = 1;
22  for j = nA3 - 1 : -1 : 0
23    m = min(nA3 - j - 1, j);
24    A3x(k) = polyval(coeff(o : o + m), n) / coeff(o + m + 1);
25    k = k + 1;
26    o = o + m + 2;
27  end
28end
29