Number of n X 2 array permutations with each element moving one space diagonally, horizontally or vertically.
A189348
Number of n X 2 array permutations with each element moving one space diagonally, horizontally or vertically.
Terms
- a(0) =1a(1) =4a(2) =13a(3) =45a(4) =160a(5) =565a(6) =2005a(7) =7108a(8) =25209a(9) =89401a(10) =317056a(11) =1124425a(12) =3987721a(13) =14142276a(14) =50154949a(15) =177872293a(16) =630816160a(17) =2237161405a(18) =7933993245a(19) =28137553540a(20) =99788579953a(21) =353895752689
External references
- oeis: A189348