Number of ways to reciprocally link elements of an 7Xn array either to themselves or to exactly two horizontal or antidiagonal neighbors.

A220637

Number of ways to reciprocally link elements of an 7Xn array either to themselves or to exactly two horizontal or antidiagonal neighbors.

Terms

    a(0) =1a(1) =1a(2) =21a(3) =1081a(4) =49448a(5) =1932695a(6) =72097810a(7) =2685329069a(8) =100377946990

External references