Incidence matrix according to Dynkin symbol

```x3x3o3o3o3o3o3o

. . . . . . . . | 72 |  1   7 |  7  21 |  21  35 |  35  35 | 35  21 | 21  7 | 7 1
----------------+----+--------+--------+---------+---------+--------+-------+----
x . . . . . . . |  2 | 36   * ♦  7   0 |  21   0 |  35   0 | 35   0 | 21  0 | 7 0
. x . . . . . . |  2 |  * 252 |  1   6 |   6  15 |  15  20 | 20  15 | 15  6 | 6 1
----------------+----+--------+--------+---------+---------+--------+-------+----
x3x . . . . . . |  6 |  3   3 | 84   * ♦   6   0 |  15   0 | 20   0 | 15  0 | 6 0
. x3o . . . . . |  3 |  0   3 |  * 504 |   1   5 |   5  10 | 10  10 | 10  5 | 5 1
----------------+----+--------+--------+---------+---------+--------+-------+----
x3x3o . . . . . ♦ 12 |  6  12 |  4   4 | 126   * ♦   5   0 | 10   0 | 10  0 | 5 0
. x3o3o . . . . ♦  4 |  0   6 |  0   4 |   * 630 |   1   4 |  4   6 |  6  4 | 4 1
----------------+----+--------+--------+---------+---------+--------+-------+----
x3x3o3o . . . . ♦ 20 | 10  30 | 10  20 |   5   5 | 126   * ♦  4   0 |  6  0 | 4 0
. x3o3o3o . . . ♦  5 |  0  10 |  0  10 |   0   5 |   * 504 |  1   3 |  3  3 | 3 1
----------------+----+--------+--------+---------+---------+--------+-------+----
x3x3o3o3o . . . ♦ 30 | 15  60 | 20  60 |  15  30 |   6   6 | 84   * |  3  0 | 3 0
. x3o3o3o3o . . ♦  6 |  0  15 |  0  20 |   0  15 |   0   6 |  * 252 |  1  2 | 2 1
----------------+----+--------+--------+---------+---------+--------+-------+----
x3x3o3o3o3o . . ♦ 42 | 21 105 | 35 140 |  35 105 |  21  42 |  7   7 | 36  * | 2 0
. x3o3o3o3o3o . ♦  7 |  0  21 |  0  35 |   0  35 |   0  21 |  0   7 |  * 72 | 1 1
----------------+----+--------+--------+---------+---------+--------+-------+----
x3x3o3o3o3o3o . ♦ 56 | 28 168 | 56 280 |  70 280 |  56 168 | 28  56 |  8  8 | 9 *
. x3o3o3o3o3o3o ♦  8 |  0  28 |  0  56 |   0  70 |   0  56 |  0  28 |  0  8 | * 9
```