Number of 3Xn 0..3 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4 and at least one element with value (x(i,j)-1) mod 4, no adjacent elements equal, and upper left element zero.
A231051
Number of 3Xn 0..3 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 4 and at least one element with value (x(i,j)-1) mod 4, no adjacent elements equal, and upper left element zero.
Terms
- a(0) =0a(1) =2a(2) =50a(3) =128a(4) =644a(5) =5100a(6) =33696a(7) =211032a(8) =1354848a(9) =8755256a(10) =56382600a(11) =362808600a(12) =2335743720a(13) =15038803080a(14) =96821412760a(15) =623339871560
External references
- oeis: A231051