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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 7 |
| 3 | 30 |
| 4 | 153 |
| 5 | 805 |
| 6 | 4397 |
| 7 | 24647 |
| 8 | 141020 |
| 9 | 820201 |
| 10 | 4835029 |
| 11 | 28823700 |
| 12 | 173471074 |
| 13 | 1052554765 |
| 14 | 6431805843 |
| 15 | 39546649026 |
| 16 | 244489418103 |
| 17 | 1518872793184 |
| 18 | 9477032121080 |
| 19 | 59364204189857 |
| 20 | 373178685365818 |
| 21 | 2353473823288829 |
| 22 | 14886098712983627 |
| 23 | 94411553259696275 |
[1,1,7,30,153,805,4397,24647,141020,820201, 4835029,28823700,173471074,1052554765,6431805843, 39546649026,244489418103,1518872793184, 9477032121080,59364204189857,373178685365818, 2353473823288829,14886098712983627, 94411553259696275] |