Number of n X n integer matrices, symmetric under 90-degree rotation, with adjacent elements differing by no more than 1, counting matrices differing by a constant only once.

A141444

Number of n X n integer matrices, symmetric under 90-degree rotation, with adjacent elements differing by no more than 1, counting matrices differing by a constant only once.

Terms

    a(0) =1a(1) =1a(2) =9a(3) =17a(4) =309a(5) =1265a(6) =48927a(7) =435807a(8) =36527739a(9) =709448287a(10) =129684847323

External references