Number of ways to reciprocally link elements of an nX7 array either to themselves or to exactly one horizontal or antidiagonal neighbor.

A220561

Number of ways to reciprocally link elements of an nX7 array either to themselves or to exactly one horizontal or antidiagonal neighbor.

Terms

    a(0) =21a(1) =1544a(2) =101052a(3) =6743873a(4) =449429440a(5) =29955561052

External references