Number of ways one can draw arrows between adjacent nodes of an n X n grid such that each node has one outgoing and one incoming arrow.
A216675
Number of ways one can draw arrows between adjacent nodes of an n X n grid such that each node has one outgoing and one incoming arrow.
Terms
- a(0) =0a(1) =4a(2) =0a(3) =1296a(4) =0a(5) =45265984a(6) =0a(8) =0a(10) =0a(12) =0a(14) =0a(16) =0
External references
- oeis: A216675