Number of (n+1)X(n+1) -8..8 symmetric matrices with every 2X2 subblock having sum zero and three or four distinct values.

A211471

Number of (n+1)X(n+1) -8..8 symmetric matrices with every 2X2 subblock having sum zero and three or four distinct values.

Terms

    a(0) =120a(1) =856a(2) =6040a(3) =42492a(4) =297572a(5) =2076768a(6) =14447284a(7) =100224428a(8) =693541160a(9) =4788481556a(10) =32994512924a(11) =226924908072

External references