Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all 1's connected only in a 1001-1111-1000 pattern in any orientation.
A146843
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all 1's connected only in a 1001-1111-1000 pattern in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =3a(9) =9a(10) =19a(11) =33a(12) =61a(13) =167a(14) =557a(15) =1931a(16) =7517a(17) =29489a(18) =124159a(19) =584129a(20) =3130749a(21) =18534977
External references
- oeis: A146843