a(n,m)  tabf head (staircase) for  A089517


 n\m         0         1           2               3                 4                   5                   6         
        
   
   3         1         0           0               0                 0                   0                   0         
                   
   4        18         0           0               0                 0                   0                   0         
                    
   5         9       432           0               0                 0                   0                   0         
                    
   6         1       672       14400               0                 0                   0                   0         
                    
   7       243     47520      648000               0                 0                   0                   0         
                   
   8        27     36396     3790800        38102400                 0                   0                   0         
                    
   9         1      9765     5115888       354715200        2844979200                   0                   0         
                 
  10      1107   2499552   757646784     39182330880      263363788800                   0                   0         
             
  11        54    546453   592216272    123294623040     5089348454400      29628426240000                   0         
        
  12         1     59085   211568688    142491117600    22403472998400     771646756608000    3983377305600000         
   
  13      3285  39020751 75951154008  36253697135040  4568855023526400  135452934650880000  630966965207040000         
   
  
  The row length sequence of this tabf entry is [1, 1, 2, 3, 3, 4, 5, 5, 6, 7, 7, ... ]= A004396(n-2), n>=3.