Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in an em 1,1 1,2 2,2 2,3 3,3 in any orientation.
A146146
Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in an em 1,1 1,2 2,2 2,3 3,3 in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =5a(7) =5a(8) =19a(9) =19a(10) =97a(11) =97a(12) =863a(13) =863a(14) =18767a(15) =18767a(16) =490889a(17) =490889a(18) =19713443a(19) =19713443a(20) =1413873475a(21) =1413873475a(22) =167866752937a(23) =167866752937
External references
- oeis: A146146