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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 19 |
| 5 | 307 |
| 6 | 5237 |
| 7 | 99137 |
| 8 | 2098946 |
| 9 | 49504458 |
| 10 | 1291570014 |
| 11 | 37002273654 |
| 12 | 1156078150969 |
| 13 | 39147186978685 |
| 14 | 1428799530304243 |
| 15 | 55933568895261791 |
| 16 | 2338378885159906196 |
| 17 | 103995520598384132516 |
| 18 | 4903038902046860966220 |
| 19 | 244294315694676224001852 |
| 20 | 12827355456239840407125363 |
[0,0,0,1,19,307,5237,99137,2098946,49504458, 1291570014,37002273654,1156078150969, 39147186978685,1428799530304243,55933568895261791, 2338378885159906196,103995520598384132516, 4903038902046860966220,244294315694676224001852, 12827355456239840407125363] |