Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 2X2 block with tail 1,1 1,2 1,3 2,2 2,3 in any orientation.
A146053
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in a 2X2 block with tail 1,1 1,2 1,3 2,2 2,3 in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =5a(4) =29a(5) =139a(6) =901a(7) =5485a(8) =74291a(9) =1056181a(10) =24810777a(11) =651071773a(12) =25748617719
External references
- oeis: A146053