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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 9 |
| 3 | 28 |
| 4 | 93 |
| 5 | 333 |
| 6 | 1269 |
| 7 | 5022 |
| 8 | 20169 |
| 9 | 80919 |
| 10 | 321489 |
| 11 | 1259712 |
| 12 | 4861701 |
| 13 | 18482337 |
| 14 | 69264477 |
| 15 | 256154562 |
| 16 | 935867601 |
| 17 | 3381559083 |
| 18 | 12096128601 |
| 19 | 42874534116 |
| 20 | 150706570221 |
| 21 | 525729603573 |
| 22 | 1821263718789 |
| 23 | 6269238352998 |
| 24 | 21454184419353 |
[1,3,9,28,93,333,1269,5022,20169,80919,321489, 1259712,4861701,18482337,69264477,256154562, 935867601,3381559083,12096128601,42874534116, 150706570221,525729603573,1821263718789, 6269238352998,21454184419353] |