1,4
A persymmetric (or Hankel) matrix has M[i,j] = M[i-k,j+k] for all i and j (matrix is constant along antidiagonals).
Cf. A034918.
Sequence in context: A003217 A178717 A006723 * A092264 A135729 A118330
Adjacent sequences: A096387 A096388 A096389 * A096391 A096392 A096393
nonn
John W. Layman (layman(AT)math.vt.edu), Aug 10 2004
a(9)-a(12) from Max Alekseyev (maxale(AT)gmail.com), Jun 16 2008