Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in two by two blocks.
A145864
Number of n X n binary arrays symmetric under 180 degree rotation with all ones connected only in two by two blocks.
Terms
- a(0) =1a(1) =2a(2) =1a(3) =4a(4) =8a(5) =25a(6) =59a(7) =294a(8) =976a(9) =6868a(10) =36894a(11) =351022a(12) =2656603a(13) =36966909a(14) =391525649a(15) =7896337875a(16) =122564741600
External references
- oeis: A145864