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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 38 |
| 5 | 161 |
| 6 | 747 |
| 7 | 3753 |
| 8 | 20253 |
| 9 | 116642 |
| 10 | 713130 |
| 11 | 4607813 |
| 12 | 31345921 |
| 13 | 223767233 |
| 14 | 1671430607 |
| 15 | 13030153118 |
| 16 | 105777688842 |
| 17 | 892355720117 |
| 18 | 7808793918123 |
| 19 | 70763428070825 |
| 20 | 663061665021433 |
| 21 | 6415290033157950 |
| 22 | 64009171867651406 |
| 23 | 657841277082303361 |
| 24 | 6956340269434938161 |
[1,1,3,10,38,161,747,3753,20253,116642,713130, 4607813,31345921,223767233,1671430607,13030153118, 105777688842,892355720117,7808793918123, 70763428070825,663061665021433,6415290033157950, 64009171867651406,657841277082303361, 6956340269434938161] |