Number of n X n binary matrices, symmetric under 180 degree rotation, with no more than 1 one in any 2 X 2 subblock.
A141488
Number of n X n binary matrices, symmetric under 180 degree rotation, with no more than 1 one in any 2 X 2 subblock.
Terms
- a(0) =1a(1) =2a(2) =1a(3) =7a(4) =14a(5) =111a(6) =277a(7) =4630a(8) =25913a(9) =702227a(10) =6394908a(11) =326629617a(12) =5687827965a(13) =509730678546
External references
- oeis: A141488