a(n,m)  tabf head (staircase) for  A034870


   n\m   0    1    2    3    4    5    6      7      8      9    10    11   12   13   14   15   16

                 
    0    1    0    0    0    0    0    0      0      0      0     0     0    0    0    0    0    0
                 
    1    1    2    1    0    0    0    0      0      0      0     0     0    0    0    0    0    0
                 
    2    1    4    6    4    1    0    0      0      0      0     0     0    0    0    0    0    0
                 
    3    1    6   15   20   15    6    1      0      0      0     0     0    0    0    0    0    0
                 
    4    1    8   28   56   70   56   28      8      1      0     0     0    0    0    0    0    0
                 
    5    1   10   45  120  210  252  210    120     45     10     1     0    0    0    0    0    0
                 
    6    1   12   66  220  495  792  924    792    495    220    66    12    1    0    0    0    0
                 
    7    1   14   91  364 1001 2002 3003   3432   3003   2002  1001   364   91   14    1    0    0
                 
    8    1   16  120  560 1820 4368 8008  11440  12870  11440  8008  4368 1820  560  120   16    1
 


The sequence of row lengths of this tabf array is [1,3,5,7,9,11,13,...]= A005408(n), n>=0.