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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 16 |
| 3 | 49 |
| 4 | 148 |
| 5 | 445 |
| 6 | 1336 |
| 7 | 4009 |
| 8 | 12028 |
| 9 | 36085 |
| 10 | 108256 |
| 11 | 324769 |
| 12 | 974308 |
| 13 | 2922925 |
| 14 | 8768776 |
| 15 | 26306329 |
| 16 | 78918988 |
| 17 | 236756965 |
| 18 | 710270896 |
| 19 | 2130812689 |
| 20 | 6392438068 |
| 21 | 19177314205 |
| 22 | 57531942616 |
| 23 | 172595827849 |
| 24 | 517787483548 |
| 25 | 1553362450645 |
[1,5,16,49,148,445,1336,4009,12028,36085,108256, 324769,974308,2922925,8768776,26306329,78918988, 236756965,710270896,2130812689,6392438068, 19177314205,57531942616,172595827849,517787483548, 1553362450645] |