Number of (n+1)X(n+1) -8..8 symmetric matrices with every 2X2 subblock having sum zero and one, three or four distinct values.
A211472
Number of (n+1)X(n+1) -8..8 symmetric matrices with every 2X2 subblock having sum zero and one, three or four distinct values.
Terms
- a(0) =121a(1) =873a(2) =6225a(3) =44205a(4) =312209a(5) =2195485a(6) =15376453a(7) =107305341a(8) =746401305a(9) =5176610637a(10) =35805913289a(11) =247058995669
External references
- oeis: A211472