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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 8 |
| 3 | 22 |
| 4 | 59 |
| 5 | 156 |
| 6 | 412 |
| 7 | 1093 |
| 8 | 2903 |
| 9 | 7707 |
| 10 | 20453 |
| 11 | 54275 |
| 12 | 144035 |
| 13 | 382255 |
| 14 | 1014469 |
| 15 | 2692284 |
| 16 | 7144989 |
| 17 | 18961928 |
| 18 | 50322686 |
| 19 | 133550412 |
| 20 | 354426839 |
| 21 | 940606403 |
| 22 | 2496256771 |
| 23 | 6624766692 |
| 24 | 17581338025 |
| 25 | 46658767166 |
| 26 | 123826784175 |
| 27 | 328621466028 |
| 28 | 872122042693 |
[1,3,8,22,59,156,412,1093,2903,7707,20453,54275, 144035,382255,1014469,2692284,7144989,18961928, 50322686,133550412,354426839,940606403,2496256771, 6624766692,17581338025,46658767166,123826784175, 328621466028,872122042693] |