Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1100-0111-0001 pattern in any orientation.
A147281
Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1100-0111-0001 pattern in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =21a(9) =49a(10) =87a(11) =289a(12) =1009a(13) =3425a(14) =11605a(15) =48481a(16) =255569a(17) =1441107a(18) =8859577a(19) =59249469a(20) =422335799
External references
- oeis: A147281