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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 |
| 15 | 32433194803107 |
| 16 | 359960491516138 |
| 17 | 3941261642520039 |
| 18 | 42679704453671033 |
| 19 | 457980431402674541 |
[0,0,0,0,20,1235,32396,605939,9446284,131733664, 1706815354,21008871506,249145286508,2873325692759, 32433194803107,359960491516138,3941261642520039, 42679704453671033,457980431402674541] |