Number of ways to reciprocally link elements of an nX4 array either to themselves or to exactly two king-move neighbors, without 3-loops.
A220649
Number of ways to reciprocally link elements of an nX4 array either to themselves or to exactly two king-move neighbors, without 3-loops.
Terms
- a(0) =1a(1) =83a(2) =4352a(3) =192413a(4) =8627817a(5) =389859889a(6) =17592276986a(7) =793772500717
External references
- oeis: A220649