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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 0 |
| 6 | 0 |
| 7 | 26 |
| 8 | 150 |
| 9 | 0 |
| 10 | 0 |
| 11 | 17792 |
| 12 | 108144 |
| 13 | 0 |
| 14 | 0 |
| 15 | 39809640 |
| 16 | 326721800 |
| 17 | 0 |
| 18 | 0 |
| 19 | 256814891280 |
| 20 | 2636337861200 |
| 21 | 0 |
| 22 | 0 |
| 23 | 3799455942515488 |
| 24 | 46845158056515936 |
| 25 | 0 |
| 26 | 0 |
| 27 | 111683611098764903232 |
| 28 | 1607383260609382393152 |
| 29 | 0 |
| 30 | 0 |
[0,0,1,1,0,0,26,150,0,0,17792,108144,0,0,39809640, 326721800,0,0,256814891280,2636337861200,0,0, 3799455942515488,46845158056515936,0,0, 111683611098764903232,1607383260609382393152,0,0] |