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| n | a(n) |
|---|---|
| 2 | 2 |
| 3 | 8 |
| 4 | 32 |
| 5 | 136 |
| 6 | 596 |
| 7 | 2712 |
| 8 | 12642 |
| 9 | 60234 |
| 10 | 291840 |
| 11 | 1434184 |
| 12 | 7130640 |
| 13 | 35807114 |
| 14 | 181339236 |
| 15 | 925139186 |
| 16 | 4750176056 |
| 17 | 24528421712 |
| 18 | 127294780994 |
| 19 | 663591911824 |
| 20 | 3473315219722 |
| 21 | 18246162722278 |
| 22 | 96169600405626 |
| 23 | 508413199626078 |
| 24 | 2695245063006696 |
| 25 | 14324688031734740 |
[2,8,32,136,596,2712,12642,60234,291840,1434184, 7130640,35807114,181339236,925139186,4750176056, 24528421712,127294780994,663591911824, 3473315219722,18246162722278,96169600405626, 508413199626078,2695245063006696, 14324688031734740] |