Number of ways to reciprocally link elements of an n X 7 array either to themselves or to exactly two horizontal, diagonal or antidiagonal neighbors.

A220724

Number of ways to reciprocally link elements of an n X 7 array either to themselves or to exactly two horizontal, diagonal or antidiagonal neighbors.

Terms

    a(0) =1a(1) =717a(2) =114900a(3) =21914482a(4) =4067687187a(5) =759141297226

External references