A persymmetric (or Hankel) matrix has M[ i,j ] = M[ i-k,j+k ] for all i and j (matrix is constant along antidiagonals).
I would love to find out what "consecutive" means here! Adjacent entries along the top row and right side must be consecutive? - N. J. A. Sloane.
Table of n, a(n) for n=1..6.
Sequence in context: A006399 A056800 A219969 * A151340 A134316 A049461
Adjacent sequences: A034916 A034917 A034918 * A034920 A034921 A034922
Fred Lunnon (fred(AT)csa5.cs.may.ie)