a(n,m) tabl head (triangle) for  A090217


  n\m              1                   2                  3                  4                5            6       7      8           
 
                   
  1                1                   0                  0                  0                0            0       0      0            
                    
  2              120                   1                  0                  0                0            0       0      0            
                   
  3            14400                 840                  1                  0                0            0       0      0            
                   
  4          1728000              619200               3360                  1                0            0       0      0            
                
  5        207360000           447552000            9086400              10080                1            0       0      0           
           
  6      24883200000        322444800000        23345280000           76824000            25200            1       0      0            
            
  7    2985984000000     232185139200000     59152550400000       539602560000        457848000        55440       1      0           
    
  8  358318080000000  167176286208000000 149296612147200000   3685281753600000    7462264320000   2134353600  110880      1