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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 34 |
| 5 | 198 |
| 6 | 1308 |
| 7 | 9651 |
| 8 | 79210 |
| 9 | 720898 |
| 10 | 7240804 |
| 11 | 79774814 |
| 12 | 957795188 |
| 13 | 12453298700 |
| 14 | 174353907960 |
| 15 | 2615339041155 |
| 16 | 41845544418330 |
| 17 | 711374726547210 |
| 18 | 12804746933817300 |
| 19 | 243290199050400810 |
| 20 | 4865804009789159580 |
| 21 | 102181884318952612980 |
| 22 | 2248001455463732796360 |
[1,1,2,7,34,198,1308,9651,79210,720898,7240804, 79774814,957795188,12453298700,174353907960, 2615339041155,41845544418330,711374726547210, 12804746933817300,243290199050400810, 4865804009789159580,102181884318952612980, 2248001455463732796360] |