a(n,m)  tabf head (staircase) for  A115139


     n\m       0         1         2         3         4         5         6         7  ...


     1         1         0         0         0         0         0         0         0
     
     
     2         1         0         0         0         0         0         0         0
                     
      
     3         1        -1         0         0         0         0         0         0
                     
     
     4         1        -2         0         0         0         0         0         0
                     
 
     5         1        -3         1         0         0         0         0         0
                     
 
     6         1        -4         3         0         0         0         0         0
                     

     7         1        -5         6        -1         0         0         0         0
                     

     8         1        -6        10        -4         0         0         0         0
                     

     9         1        -7        15       -10         1         0         0         0
                    
    
    10         1        -8        21       -20         5         0         0         0
                    

    11         1        -9        28       -35        15        -1         0         0
                    
   
    12         1       -10        36       -56        35        -6         0         0
                    

    13         1       -11        45       -84        70       -21         1         0
                    

    14         1       -12        55      -120       126       -56         7         0
                    
    
    15         1       -13        66      -165       210      -126        28        -1
                    

    16         1       -14        78      -220       330      -252        84        -8
     .

     .

     .

 The (signed) row sums give the periodic sequence (period 6):  [1,1,0,-1,-1,0,...]=A010892(n-1), n>=1.

 The unsigned  row sums give: A000045(n-1), n>=1, (Fibonacci).

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