Number of ways to reciprocally link elements of an nX4 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without 3-loops.

A220598

Number of ways to reciprocally link elements of an nX4 array either to themselves or to exactly two horizontal, vertical and antidiagonal neighbors, without 3-loops.

Terms

    a(0) =1a(1) =17a(2) =471a(3) =9047a(4) =167614a(5) =3174778a(6) =60138423a(7) =1137615308a(8) =21523535122a(9) =407249783145

External references