OFFSET
1,4
COMMENTS
A persymmetric (or Hankel) matrix has M[i,j] = M[i-k,j+k] for all i and j (matrix is constant along antidiagonals).
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
John W. Layman, Aug 10 2004
EXTENSIONS
a(9)-a(12) from Max Alekseyev, Jun 16 2008
STATUS
approved