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| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 12 |
| 3 | 52 |
| 4 | 216 |
| 5 | 872 |
| 6 | 3496 |
| 7 | 14024 |
| 8 | 56200 |
| 9 | 224904 |
| 10 | 899720 |
| 11 | 3599496 |
| 12 | 14398600 |
| 13 | 57599112 |
| 14 | 230398088 |
| 15 | 921606280 |
| 16 | 3686471816 |
| 17 | 14745933960 |
| 18 | 58983782536 |
| 19 | 235935438984 |
| 20 | 943742064776 |
| 21 | 3774970665096 |
| 22 | 15099883493512 |
| 23 | 60399541098632 |
| 24 | 241598171519112 |
| 25 | 966392760309896 |
[2,12,52,216,872,3496,14024,56200,224904,899720, 3599496,14398600,57599112,230398088,921606280, 3686471816,14745933960,58983782536,235935438984, 943742064776,3774970665096,15099883493512, 60399541098632,241598171519112,966392760309896] |