Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only either four adjacent vertically or four adjacent horizontally.
A145793
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only either four adjacent vertically or four adjacent horizontally.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =2a(6) =3a(7) =5a(8) =8a(9) =17a(10) =40a(11) =108a(12) =294a(13) =944a(14) =3040a(15) =12114a(16) =49757a(17) =243775a(18) =1210271a(19) =7153531a(20) =43484383a(21) =316861269a(22) =2366046579a(23) =21108349931a(24) =192219307524
External references
- oeis: A145793