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| n | a(n) |
|---|---|
| 2 | 1 |
| 3 | 11 |
| 4 | 84 |
| 5 | 557 |
| 6 | 3446 |
| 7 | 20514 |
| 8 | 119336 |
| 9 | 684227 |
| 10 | 3886460 |
| 11 | 21939528 |
| 12 | 123347842 |
| 13 | 691644044 |
| 14 | 3871738018 |
| 15 | 21652138770 |
| 16 | 121026492186 |
| 17 | 676391629701 |
| 18 | 3780636102222 |
| 19 | 21137831159462 |
| 20 | 118234019051048 |
| 21 | 661686074145618 |
| 22 | 3705252204960252 |
[1,11,84,557,3446,20514,119336,684227,3886460, 21939528,123347842,691644044,3871738018, 21652138770,121026492186,676391629701, 3780636102222,21137831159462,118234019051048, 661686074145618,3705252204960252] |