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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 3 |
| 2 | 9 |
| 3 | 26 |
| 4 | 78 |
| 5 | 234 |
| 6 | 702 |
| 7 | 2106 |
| 8 | 6318 |
| 9 | 18954 |
| 10 | 56862 |
| 11 | 170586 |
| 12 | 511758 |
| 13 | 1535274 |
| 14 | 4605822 |
| 15 | 13817466 |
| 16 | 41452398 |
| 17 | 124357194 |
| 18 | 373071582 |
| 19 | 1119214746 |
| 20 | 3357644238 |
| 21 | 10072932714 |
| 22 | 30218798142 |
| 23 | 90656394426 |
| 24 | 271969183278 |
| 25 | 815907549834 |
[0,3,9,26,78,234,702,2106,6318,18954,56862,170586, 511758,1535274,4605822,13817466,41452398, 124357194,373071582,1119214746,3357644238, 10072932714,30218798142,90656394426,271969183278, 815907549834] |