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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 10 |
| 3 | 32 |
| 4 | 104 |
| 5 | 345 |
| 6 | 1166 |
| 7 | 4004 |
| 8 | 13936 |
| 9 | 49062 |
| 10 | 174420 |
| 11 | 625328 |
| 12 | 2258416 |
| 13 | 8209045 |
| 14 | 30008790 |
| 15 | 110255100 |
| 16 | 406923360 |
| 17 | 1507973610 |
| 18 | 5608843020 |
| 19 | 20931740640 |
| 20 | 78354322800 |
| 21 | 294127079610 |
| 22 | 1106939020044 |
| 23 | 4175827174152 |
| 24 | 15787544777504 |
[1,3,10,32,104,345,1166,4004,13936,49062,174420, 625328,2258416,8209045,30008790,110255100, 406923360,1507973610,5608843020,20931740640, 78354322800,294127079610,1106939020044, 4175827174152,15787544777504] |