Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only either two adjacent vertically or two adjacent horizontally.
A145780
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only either two adjacent vertically or two adjacent horizontally.
Terms
- a(0) =1a(1) =1a(2) =5a(3) =18a(4) =70a(5) =523a(6) =4956a(7) =70926a(8) =1300201a(9) =37116376a(10) =1354115636a(11) =76887328413
External references
- oeis: A145780