Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1100-0111-1100 pattern in any orientation.
A146680
Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1100-0111-1100 pattern in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =9a(8) =20a(9) =33a(10) =56a(11) =137a(12) =404a(13) =1209a(14) =4087a(15) =15733a(16) =60343a(17) =254309a(18) =1153606a(19) =5642466a(20) =31006709a(21) =182836767a(22) =1183007758a(23) =8378875432a(24) =64857203324
External references
- oeis: A146680