###   a(k, m)  tabf head (staircase) for  A103718

k/m          0           1          2           3         4          5        6        7      8      9   10  11 12 ...
-------------------------------------------------------------------------------------------------------------------------------
0:           1
1:           2          -1
2:           5          -4          1
3:          17         -17          7          -1
4:          74         -85         45         -11         1
5:         394        -499        310        -100        16         -1
6:        2484       -3388       2359        -910       196        -22        1
7:       18108      -26200      19901       -8729      2282       -350       29       -1
8:      149904     -227708     185408      -89733     26985      -5082      582      -37      1
9:     1389456    -2199276    1896380     -993005    332598     -72723    10320     -915     46     -1  
10:   14257440   -23382216   21163076   -11826430   4318985   -1059828   175923   -19470   1375    -56    1
11:  160460640  -271461816  256176052  -151253806  59335265  -15977093  2994981  -390093  34595  -1991   67  -1
12: 1965444480 -3418002432 3345574440 -2071221724 863276986 -251060381 51916865 -7676097 805233 -58487 2795 -79  1
...

13: 26029779840, -46399476096, 46910470152, -30271456852, 13293822542, -4127061939, 925979626, -151706126, 18144126, -1565564,
  94822, -3822, 92, -1,
14: 370643938560 -675622445184 703146058224 -470710866080 216384972440 -71072689688 17090776703 -3049865390 405723890 -40062022 
  2893072 -148330 5110 -106 1,
15: 5646837369600 -10504980616320 11222813318544 -7763809049424 3716485452680 -1282475317760 327434340233 -62838757553 
  9135723740 -1006654220 83458102 -5118022 224980 -6700 121 -1,
...
----------------------------------------------------- eof -----------------------------------------------------------------------