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

A220546

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

Terms

    a(0) =1a(1) =8a(2) =224a(3) =32173a(4) =21668208a(5) =69961268156

External references