Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1000-1111-0010-0010 pattern in any orientation.
A147172
Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a 1000-1111-0010-0010 pattern in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =9a(9) =9a(10) =33a(11) =33a(12) =81a(13) =81a(14) =501a(15) =501a(16) =9129a(17) =9129a(18) =252307a(19) =252307a(20) =4894765a(21) =4894765
External references
- oeis: A147172