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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 17 |
| 6 | 4130 |
| 7 | 246498 |
| 8 | 6833514 |
| 9 | 114889560 |
| 10 | 1350364581 |
| 11 | 12098859685 |
| 12 | 87508246816 |
| 13 | 531900780705 |
| 14 | 2798253712804 |
| 15 | 13029075803653 |
| 16 | 54632738218122 |
| 17 | 209171316078609 |
| 18 | 739462342785714 |
| 19 | 2436048010628520 |
| 20 | 7535911103201627 |
[0,0,0,0,17,4130,246498,6833514,114889560, 1350364581,12098859685,87508246816,531900780705, 2798253712804,13029075803653,54632738218122, 209171316078609,739462342785714,2436048010628520, 7535911103201627] |