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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 14 |
| 4 | 45 |
| 5 | 284 |
| 6 | 1570 |
| 7 | 9267 |
| 8 | 70189 |
| 9 | 496232 |
| 10 | 4010526 |
| 11 | 34481105 |
| 12 | 308516868 |
| 13 | 2926837289 |
| 14 | 29200525341 |
| 15 | 307118111601 |
| 16 | 3309789462677 |
| 17 | 37814191683984 |
| 18 | 445615694701030 |
| 19 | 5424871661765829 |
| 20 | 68774736287172136 |
| 21 | 898086216694079703 |
| 22 | 12111344019974440847 |
[1,1,3,14,45,284,1570,9267,70189,496232,4010526, 34481105,308516868,2926837289,29200525341, 307118111601,3309789462677,37814191683984, 445615694701030,5424871661765829, 68774736287172136,898086216694079703, 12111344019974440847] |