1/256 the number of (n+1) X 3 0..3 arrays with no 2 X 2 subblock being a reflection across the shared element pair of any horizontal or vertical neighbor.
A183821
1/256 the number of (n+1) X 3 0..3 arrays with no 2 X 2 subblock being a reflection across the shared element pair of any horizontal or vertical neighbor.
Terms
- a(0) =15a(1) =813a(2) =43947a(3) =2377341a(4) =128578815a(5) =6954559893a(6) =376152548283
External references
- oeis: A183821