Number of ways to reciprocally link elements of an n X n array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

A220615

Number of ways to reciprocally link elements of an n X n array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

Terms

    a(0) =1a(1) =7a(2) =125a(3) =17084a(4) =8608738a(5) =24177895648

External references