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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 12 |
| 3 | 57 |
| 4 | 301 |
| 5 | 1700 |
| 6 | 10045 |
| 7 | 61303 |
| 8 | 383335 |
| 9 | 2443113 |
| 10 | 15811317 |
| 11 | 103627692 |
| 12 | 686402602 |
| 13 | 4587643765 |
| 14 | 30900426417 |
| 15 | 209539509967 |
| 16 | 1429344492215 |
| 17 | 9801262309209 |
| 18 | 67523359213569 |
| 19 | 467136798336153 |
| 20 | 3243948604314619 |
| 21 | 22604271635042853 |
| 22 | 158001453530915361 |
[1,3,12,57,301,1700,10045,61303,383335,2443113, 15811317,103627692,686402602,4587643765, 30900426417,209539509967,1429344492215, 9801262309209,67523359213569,467136798336153, 3243948604314619,22604271635042853, 158001453530915361] |