Number of n X n binary arrays symmetric about main diagonal with all 1's connected only in a 2 X 2 block with tail 1,1 1,2 1,3 2,2 2,3 in any orientation.
A146049
Number of n X n binary arrays symmetric about main diagonal with all 1's connected only in a 2 X 2 block with tail 1,1 1,2 1,3 2,2 2,3 in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =3a(4) =13a(5) =35a(6) =181a(7) =1303a(8) =13131a(9) =161693a(10) =2592581a(11) =57377381a(12) =1720164275a(13) =69927099465
External references
- oeis: A146049