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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 8 |
| 4 | 25 |
| 5 | 85 |
| 6 | 334 |
| 7 | 1497 |
| 8 | 7635 |
| 9 | 43738 |
| 10 | 278415 |
| 11 | 1949531 |
| 12 | 14893000 |
| 13 | 123254221 |
| 14 | 1098523231 |
| 15 | 10490117340 |
| 16 | 106851450165 |
| 17 | 1156403632189 |
| 18 | 13251409502982 |
| 19 | 160286076269309 |
| 20 | 2040825708462175 |
| 21 | 27283829950774822 |
| 22 | 382127363497453243 |
| 23 | 5595206208670390323 |
[0,1,3,8,25,85,334,1497,7635,43738,278415,1949531, 14893000,123254221,1098523231,10490117340, 106851450165,1156403632189,13251409502982, 160286076269309,2040825708462175, 27283829950774822,382127363497453243, 5595206208670390323] |