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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 20 |
| 3 | 310 |
| 4 | 4400 |
| 5 | 60100 |
| 6 | 806000 |
| 7 | 10711000 |
| 8 | 141680000 |
| 9 | 1869610000 |
| 10 | 24641000000 |
| 11 | 324555100000 |
| 12 | 4273412000000 |
| 13 | 56258281000000 |
| 14 | 740558540000000 |
| 15 | 9747925510000000 |
| 16 | 128308241600000000 |
| 17 | 1688851536100000000 |
| 18 | 22229288978000000000 |
| 19 | 292589141311000000000 |
[0,1,20,310,4400,60100,806000,10711000,141680000, 1869610000,24641000000,324555100000,4273412000000, 56258281000000,740558540000000,9747925510000000, 128308241600000000,1688851536100000000, 22229288978000000000,292589141311000000000] |