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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 19 |
| 5 | 54 |
| 6 | 164 |
| 7 | 476 |
| 8 | 1417 |
| 9 | 4087 |
| 10 | 12589 |
| 11 | 37818 |
| 12 | 116828 |
| 13 | 358277 |
| 14 | 1106870 |
| 15 | 3460676 |
| 16 | 10813998 |
| 17 | 34339769 |
| 18 | 109194390 |
| 19 | 350181146 |
| 20 | 1126919513 |
| 21 | 3634208553 |
| 22 | 11774823887 |
| 23 | 38335906599 |
| 24 | 125461951555 |
| 25 | 411934520324 |
| 26 | 1356668825821 |
[1,2,7,19,54,164,476,1417,4087,12589,37818,116828, 358277,1106870,3460676,10813998,34339769, 109194390,350181146,1126919513,3634208553, 11774823887,38335906599,125461951555,411934520324, 1356668825821] |