Number of n X n binary arrays symmetric under 90-degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally.
A145763
Number of n X n binary arrays symmetric under 90-degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =4a(5) =7a(6) =16a(7) =35a(8) =133a(9) =363a(10) =1590a(11) =5600a(12) =33892a(13) =154647a(14) =1163836a(15) =6812622a(16) =66760064a(17) =504710757a(18) =6331779830a(19) =61565739001a(20) =996948455181
External references
- oeis: A145763