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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 27 |
| 5 | 79 |
| 6 | 237 |
| 7 | 705 |
| 8 | 2115 |
| 9 | 6327 |
| 10 | 18981 |
| 11 | 56889 |
| 12 | 170667 |
| 13 | 511843 |
| 14 | 1535529 |
| 15 | 4606113 |
| 16 | 13818339 |
| 17 | 41453607 |
| 18 | 124360821 |
| 19 | 373078233 |
| 20 | 1119234699 |
| 21 | 3357691443 |
| 22 | 10073074329 |
| 23 | 30219185025 |
| 24 | 90657555075 |
| 25 | 271972551447 |
| 26 | 815917654341 |
[0,1,3,9,27,79,237,705,2115,6327,18981,56889, 170667,511843,1535529,4606113,13818339,41453607, 124360821,373078233,1119234699,3357691443, 10073074329,30219185025,90657555075,271972551447, 815917654341] |