lar matrix C2out (see
          METHOD), and the (N/2-1)-by-(N/2-1) upper triangular part
          of the submatrix in the columns 3 to N/2+1 of this array
          contains the strictly upper triangular part of the
          skew-symmetric matrix Dout (see METHOD), without the main
          diagonal, which is zero.
          On exit, if COMPQ = 'N', the leading N/2-by-N/2 lower
          triangular part and the first superdiagonal contain the
          transpose of the upper Hessenberg matrix C2, and th