Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 00100-11111-00100 pattern in any orientation.
A147007
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 00100-11111-00100 pattern in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =2a(9) =3a(10) =6a(11) =9a(12) =14a(13) =23a(14) =57a(15) =131a(16) =385a(17) =909a(18) =2527a(19) =6618a(20) =23479
External references
- oeis: A147007