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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 14 |
| 5 | 46 |
| 6 | 242 |
| 7 | 1114 |
| 8 | 7814 |
| 9 | 46246 |
| 10 | 405482 |
| 11 | 2933074 |
| 12 | 30860414 |
| 13 | 263817646 |
| 14 | 3238391522 |
| 15 | 31943268634 |
| 16 | 448122565814 |
| 17 | 5009616448246 |
| 18 | 79063212894362 |
| 19 | 987840438629794 |
| 20 | 17322647732052014 |
| 21 | 239217148602642046 |
| 22 | 4614370558369770002 |
| 23 | 69790939492563608554 |
[1,1,2,4,14,46,242,1114,7814,46246,405482,2933074, 30860414,263817646,3238391522,31943268634, 448122565814,5009616448246,79063212894362, 987840438629794,17322647732052014, 239217148602642046,4614370558369770002, 69790939492563608554] |