Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1000-1111-0001 pattern in any orientation.
A147273
Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1000-1111-0001 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) =41a(10) =79a(11) =171a(12) =645a(13) =1743a(14) =5843a(15) =17953a(16) =98853a(17) =402491a(18) =2708743a(19) =12396159
External references
- oeis: A147273