Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1101-0111-0010 pattern in any orientation.
A147243
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1101-0111-0010 pattern in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =3a(7) =5a(8) =11a(9) =21a(10) =39a(11) =109a(12) =383a(13) =1291a(14) =5187a(15) =19147a(16) =85163a(17) =418695a(18) =2523925a(19) =15886439a(20) =116954773a(21) =866328129
External references
- oeis: A147243