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| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 0 |
| 5 | 2 |
| 6 | 3 |
| 7 | 54 |
| 8 | 0 |
| 9 | 30 |
| 10 | 105 |
| 11 | 6090 |
| 12 | 1512 |
| 13 | 133056 |
| 14 | 816480 |
| 15 | 127209600 |
| 16 | 0 |
| 17 | 10090080 |
| 18 | 562161600 |
| 19 | 69864795000 |
| 20 | 49989139200 |
| 21 | 29593652088000 |
| 22 | 382147120555200 |
| 23 | 41810689605484800 |
| 24 | 4359985823793600 |
| 25 | 3025062801079038720 |
| 26 | 49052072750637116160 |
| 27 | 25835971971637227375360 |
[1,1,1,2,0,2,3,54,0,30,105,6090,1512,133056, 816480,127209600,0,10090080,562161600,69864795000, 49989139200,29593652088000,382147120555200, 41810689605484800,4359985823793600, 3025062801079038720,49052072750637116160, 25835971971637227375360] |