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| n | a(n) |
|---|---|
| 1 | 268 |
| 2 | 984 |
| 3 | 3284 |
| 4 | 10888 |
| 5 | 36180 |
| 6 | 120540 |
| 7 | 401520 |
| 8 | 1336540 |
| 9 | 4448892 |
| 10 | 14811704 |
| 11 | 49313092 |
| 12 | 164172108 |
| 13 | 546554288 |
| 14 | 1819586828 |
| 15 | 6057775468 |
| 16 | 20167512408 |
| 17 | 67141506132 |
| 18 | 223527096380 |
| 19 | 744165226864 |
| 20 | 2477470556540 |
| 21 | 8247979825436 |
[268,984,3284,10888,36180,120540,401520,1336540, 4448892,14811704,49313092,164172108,546554288, 1819586828,6057775468,20167512408,67141506132, 223527096380,744165226864,2477470556540, 8247979825436] |