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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 10 |
| 3 | 72 |
| 4 | 503 |
| 5 | 3517 |
| 6 | 24546 |
| 7 | 171268 |
| 8 | 1194876 |
| 9 | 8335964 |
| 10 | 58154668 |
| 11 | 405706565 |
| 12 | 2830343128 |
| 13 | 19745403738 |
| 14 | 137750412592 |
| 15 | 960992030353 |
| 16 | 6704195338721 |
| 17 | 46770663635910 |
| 18 | 326287475880302 |
| 19 | 2276288352727268 |
| 20 | 15880133462880199 |
[1,10,72,503,3517,24546,171268,1194876,8335964, 58154668,405706565,2830343128,19745403738, 137750412592,960992030353,6704195338721, 46770663635910,326287475880302,2276288352727268, 15880133462880199] |