Number of n X n binary arrays, symmetric under 90-degree rotation, with every 1 adjacent to at least one other 1, but at most one 1 adjacent horizontally and at most one 1 adjacent vertically.
A144058
Number of n X n binary arrays, symmetric under 90-degree rotation, with every 1 adjacent to at least one other 1, but at most one 1 adjacent horizontally and at most one 1 adjacent vertically.
Terms
- a(0) =1a(1) =2a(2) =1a(3) =5a(4) =17a(5) =65a(6) =213a(7) =1787a(8) =9524a(9) =116339a(10) =1060737a(11) =20603151a(12) =287231280a(13) =9041569891a(14) =204033795980
External references
- oeis: A144058