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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 12 |
| 4 | 32 |
| 5 | 88 |
| 6 | 260 |
| 7 | 800 |
| 8 | 2604 |
| 9 | 8824 |
| 10 | 31340 |
| 11 | 115568 |
| 12 | 443760 |
| 13 | 1763456 |
| 14 | 7260256 |
| 15 | 30835712 |
| 16 | 135124496 |
| 17 | 609027360 |
| 18 | 2822461648 |
| 19 | 13417923008 |
| 20 | 65401203584 |
| 21 | 326242088064 |
| 22 | 1664539966400 |
| 23 | 8674167861760 |
| 24 | 46140838036160 |
| 25 | 250248380068736 |
| 26 | 1383064482739392 |
| 27 | 7782094359642880 |
[1,2,5,12,32,88,260,800,2604,8824,31340,115568, 443760,1763456,7260256,30835712,135124496, 609027360,2822461648,13417923008,65401203584, 326242088064,1664539966400,8674167861760, 46140838036160,250248380068736,1383064482739392, 7782094359642880] |