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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 6 |
| 5 | 11 |
| 6 | 110 |
| 7 | 232 |
| 8 | 3136 |
| 9 | 10032 |
| 10 | 141492 |
| 11 | 561001 |
| 12 | 9708864 |
| 13 | 43864471 |
| 14 | 886873780 |
| 15 | 4775054571 |
| 16 | 106484438048 |
| 17 | 651701988633 |
| 18 | 16430255716392 |
| 19 | 111498817293652 |
| 20 | 3124376125290804 |
| 21 | 23598473924038152 |
| 22 | 721819990948712614 |
| 23 | 5975067276022072669 |
| 24 | 199594173117826648968 |
[1,0,1,1,6,11,110,232,3136,10032,141492,561001, 9708864,43864471,886873780,4775054571, 106484438048,651701988633,16430255716392, 111498817293652,3124376125290804, 23598473924038152,721819990948712614, 5975067276022072669,199594173117826648968] |