Number of ways to reciprocally link elements of an n X 4 array either to themselves or to exactly one king-move neighbor.

A220640

Number of ways to reciprocally link elements of an n X 4 array either to themselves or to exactly one king-move neighbor.

Terms

    a(0) =1a(1) =5a(2) =172a(3) =3755a(4) =92801a(5) =2226936a(6) =53841725a(7) =1299348473a(8) =31371388772a(9) =757341382671

External references