Number of ways to reciprocally link elements of an 4Xn array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

A220623

Number of ways to reciprocally link elements of an 4Xn array either to themselves or to exactly one horizontal, diagonal and antidiagonal neighbor.

Terms

    a(0) =1a(1) =71a(2) =765a(3) =17084a(4) =282777a(5) =5280827a(6) =93905509a(7) =1703300073a(8) =30648000256a(9) =553256525421

External references