Number of n X n binary matrices, symmetric under 180 degree rotation, with no more than 2 ones in any 2 X 2 subblock.
A141508
Number of n X n binary matrices, symmetric under 180 degree rotation, with no more than 2 ones in any 2 X 2 subblock.
Terms
- a(0) =1a(1) =2a(2) =3a(3) =19a(4) =93a(5) =1575a(6) =21225a(7) =1007325a(8) =39296735a(9) =5294789855a(10) =584025270873
External references
- oeis: A141508