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| n | a(n) |
|---|---|
| 1 | 6 |
| 2 | 18 |
| 3 | 84 |
| 4 | 264 |
| 5 | 705 |
| 6 | 1739 |
| 7 | 4129 |
| 8 | 9518 |
| 9 | 21271 |
| 10 | 46019 |
| 11 | 96412 |
| 12 | 195879 |
| 13 | 386603 |
| 14 | 742477 |
| 15 | 1389545 |
| 16 | 2537385 |
| 17 | 4526097 |
| 18 | 7895059 |
| 19 | 13481452 |
| 20 | 22558778 |
| 21 | 37028253 |
| 22 | 59679103 |
| 23 | 94537481 |
| 24 | 147328016 |
| 25 | 226076963 |
| 26 | 341891611 |
| 27 | 509957092 |
| 28 | 750799089 |
| 29 | 1091869239 |
[6,18,84,264,705,1739,4129,9518,21271,46019,96412, 195879,386603,742477,1389545,2537385,4526097, 7895059,13481452,22558778,37028253,59679103, 94537481,147328016,226076963,341891611,509957092, 750799089,1091869239] |