Number of n X n binary arrays symmetric under horizontal and vertical reflection with all 1's connected only in a 2 X 4 tee 1,1 1,2 1,3 2,3 1,4 in any orientation.
A146040
Number of n X n binary arrays symmetric under horizontal and vertical reflection with all 1's connected only in a 2 X 4 tee 1,1 1,2 1,3 2,3 1,4 in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =29a(9) =29a(10) =249a(11) =249a(12) =4021a(13) =4021a(14) =99935a(15) =99935a(16) =4398251a(17) =4398251a(18) =362789159a(19) =362789159a(20) =47338031953a(21) =47338031953
External references
- oeis: A146040