Number of ways to reciprocally link elements of an n X 4 array either to themselves or to exactly one horizontal or antidiagonal neighbor.

A220558

Number of ways to reciprocally link elements of an n X 4 array either to themselves or to exactly one horizontal or antidiagonal neighbor.

Terms

    a(0) =5a(1) =47a(2) =430a(3) =3966a(4) =36640a(5) =338581a(6) =3128843a(7) =28913910a(8) =267196106a(9) =2469184016a(10) =22817958901a(11) =210862878471

External references