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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 96 |
| 5 | 12840 |
| 6 | 239040 |
| 7 | 2163840 |
| 8 | 12888960 |
| 9 | 58042656 |
| 10 | 213615360 |
| 11 | 674570160 |
| 12 | 1888587360 |
| 13 | 4797335400 |
| 14 | 11245730496 |
| 15 | 24642268560 |
| 16 | 50981199360 |
| 17 | 100370578560 |
| 18 | 189249592320 |
| 19 | 343524515616 |
| 20 | 602905753440 |
| 21 | 1026789137640 |
| 22 | 1702093525440 |
| 23 | 2753544282720 |
| 24 | 4356978950016 |
| 25 | 6756347796000 |
| 26 | 10285188576000 |
[0,0,0,96,12840,239040,2163840,12888960,58042656, 213615360,674570160,1888587360,4797335400, 11245730496,24642268560,50981199360,100370578560, 189249592320,343524515616,602905753440, 1026789137640,1702093525440,2753544282720, 4356978950016,6756347796000,10285188576000] |