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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 20 |
| 6 | 1235 |
| 7 | 32396 |
| 8 | 605939 |
| 9 | 9446284 |
| 10 | 131733664 |
| 11 | 1706815354 |
| 12 | 21008871506 |
| 13 | 249145286508 |
| 14 | 2873325692759 |
[0,0,0,0,20,1235,32396,605939,9446284,131733664, 1706815354,21008871506,249145286508,2873325692759] |