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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 3 |
| 6 | 15 |
| 7 | 15 |
| 8 | 105 |
| 9 | 105 |
| 10 | 945 |
| 11 | 945 |
| 12 | 10395 |
| 13 | 10395 |
| 14 | 135135 |
| 15 | 135135 |
| 16 | 2027025 |
| 17 | 2027025 |
| 18 | 34459425 |
| 19 | 34459425 |
| 20 | 654729075 |
| 21 | 654729075 |
| 22 | 13749310575 |
| 23 | 13749310575 |
| 24 | 316234143225 |
| 25 | 316234143225 |
| 26 | 7905853580625 |
| 27 | 7905853580625 |
| 28 | 213458046676875 |
| 29 | 213458046676875 |
[1,1,1,1,3,3,15,15,105,105,945,945,10395,10395, 135135,135135,2027025,2027025,34459425,34459425, 654729075,654729075,13749310575,13749310575, 316234143225,316234143225,7905853580625, 7905853580625,213458046676875,213458046676875] |