Number of (n+1)X(n+1) -8..8 symmetric matrices with every 2X2 subblock having sum zero and two, three or four distinct values.
A211473
Number of (n+1)X(n+1) -8..8 symmetric matrices with every 2X2 subblock having sum zero and two, three or four distinct values.
Terms
- a(0) =144a(1) =1224a(2) =10416a(3) =88776a(4) =757784a(5) =6478064a(6) =55460120a(7) =475479800a(8) =4082006352a(9) =35089391112a(10) =301998774840
External references
- oeis: A211473