Number of n X n binary matrices, symmetric about both diagonal and antidiagonal, with no more than 3 ones in any 2 X 2 subblock.
A141511
Number of n X n binary matrices, symmetric about both diagonal and antidiagonal, with no more than 3 ones in any 2 X 2 subblock.
Terms
- a(0) =1a(1) =2a(2) =3a(3) =13a(4) =40a(5) =313a(6) =1833a(7) =27784a(8) =312227a(9) =9039597a(10) =194485968a(11) =10791499905a(12) =444739929613
External references
- oeis: A141511