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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 22 |
| 6 | 92 |
| 7 | 423 |
| 8 | 2093 |
| 9 | 10994 |
| 10 | 60744 |
| 11 | 350743 |
| 12 | 2106422 |
| 13 | 13110304 |
| 14 | 84330164 |
| 15 | 559367278 |
| 16 | 3819233961 |
| 17 | 26802388190 |
| 18 | 193080823079 |
| 19 | 1426252354150 |
| 20 | 10792528835886 |
| 21 | 83587157097544 |
| 22 | 662060553448763 |
| 23 | 5358900630188358 |
| 24 | 44296806348364981 |
[1,1,1,2,6,22,92,423,2093,10994,60744,350743, 2106422,13110304,84330164,559367278,3819233961, 26802388190,193080823079,1426252354150, 10792528835886,83587157097544,662060553448763, 5358900630188358,44296806348364981] |