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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 6 |
| 3 | 42 |
| 4 | 346 |
| 5 | 3310 |
| 6 | 36194 |
| 7 | 446054 |
| 8 | 6122442 |
| 9 | 92668302 |
| 10 | 1533812722 |
| 11 | 27565147126 |
| 12 | 534621745178 |
| 13 | 11131104732254 |
| 14 | 247646911102530 |
| 15 | 5863652049020358 |
| 16 | 147225092025474154 |
| 17 | 3907328980930705966 |
| 18 | 109297865960259305618 |
| 19 | 3214017757399205062550 |
| 20 | 99121172016580291190970 |
[0,1,6,42,346,3310,36194,446054,6122442,92668302, 1533812722,27565147126,534621745178, 11131104732254,247646911102530,5863652049020358, 147225092025474154,3907328980930705966, 109297865960259305618,3214017757399205062550, 99121172016580291190970] |