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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 4 |
| 4 | 6 |
| 5 | 13 |
| 6 | 48 |
| 7 | 150 |
| 8 | 300 |
| 9 | 666 |
| 10 | 936 |
| 11 | 1824 |
| 12 | 2520 |
| 13 | 2160 |
| 14 | 5040 |
| 15 | 75 |
| 16 | 536 |
| 17 | 2820 |
| 18 | 11144 |
| 19 | 41346 |
| 20 | 131304 |
| 21 | 420084 |
| 22 | 1191552 |
| 23 | 3427008 |
| 24 | 9207456 |
| 25 | 23466720 |
| 26 | 61522560 |
| 27 | 141553560 |
| 28 | 345346560 |
| 29 | 777152160 |
| 30 | 1635096960 |
| 31 | 3700806480 |
| 32 | 6998261760 |
| 33 | 14211912960 |
| 34 | 27442437120 |
[1,1,3,4,6,13,48,150,300,666,936,1824,2520,2160, 5040,75,536,2820,11144,41346,131304,420084, 1191552,3427008,9207456,23466720,61522560, 141553560,345346560,777152160,1635096960, 3700806480,6998261760,14211912960,27442437120] |