Number of (n+2) X (2+2) 0..2 arrays with every 3 X 3 subblock row and column sum 2 3 or 4 and every diagonal and antidiagonal sum not 2 3 or 4.
A252222
Number of (n+2) X (2+2) 0..2 arrays with every 3 X 3 subblock row and column sum 2 3 or 4 and every diagonal and antidiagonal sum not 2 3 or 4.
Terms
- a(0) =368a(1) =1028a(2) =3066a(3) =7724a(4) =22256a(5) =70284a(6) =219824a(7) =675264a(8) =2072804a(9) =6383492a(10) =19670396a(11) =60581792a(12) =186548780a(13) =574478144a(14) =1769185920a(15) =5448417444a(16) =16778894996a(17) =51672129164a(18) =159129275664a(19) =490053971084
External references
- oeis: A252222