Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 3X3 tee 1,1 1,2 1,3 2,2 3,2 in any orientation.
A146010
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 3X3 tee 1,1 1,2 1,3 2,2 3,2 in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =2a(7) =5a(8) =10a(9) =17a(10) =41a(11) =113a(12) =371a(13) =1287a(14) =4551a(15) =19076a(16) =90597a(17) =483533a(18) =2906704a(19) =18699832a(20) =136658284a(21) =1121369297a(22) =10362476826a(23) =106541327541
External references
- oeis: A146010