Number of ways to reciprocally link elements of an n X n array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without 3-loops.

A220596

Number of ways to reciprocally link elements of an n X n array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without 3-loops.

Terms

    a(0) =1a(1) =2a(2) =65a(3) =9047a(4) =7558495a(5) =41011388731

External references