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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 11 |
| 5 | 26 |
| 6 | 64 |
| 7 | 159 |
| 8 | 402 |
| 9 | 1032 |
| 10 | 2677 |
| 11 | 7010 |
| 12 | 18510 |
| 13 | 49220 |
| 14 | 131691 |
| 15 | 354282 |
| 16 | 957745 |
| 17 | 2600382 |
| 18 | 7088008 |
| 19 | 19388719 |
| 20 | 53207441 |
| 21 | 146444424 |
| 22 | 404151643 |
| 23 | 1118132954 |
| 24 | 3100540971 |
| 25 | 8615945102 |
| 26 | 23989662824 |
| 27 | 66917894562 |
| 28 | 186983937758 |
| 29 | 523314016245 |
| 30 | 1466807316032 |
[1,1,2,5,11,26,64,159,402,1032,2677,7010,18510, 49220,131691,354282,957745,2600382,7088008, 19388719,53207441,146444424,404151643,1118132954, 3100540971,8615945102,23989662824,66917894562, 186983937758,523314016245,1466807316032] |