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| n | a(n) |
|---|---|
| 3 | 0 |
| 4 | 0 |
| 5 | 27 |
| 6 | 999 |
| 7 | 11565 |
| 8 | 74811 |
| 9 | 342042 |
| 10 | 1239525 |
| 11 | 3799488 |
| 12 | 10259640 |
| 13 | 25076952 |
| 14 | 56552364 |
| 15 | 119324403 |
| 16 | 238062357 |
| 17 | 452774595 |
| 18 | 826245798 |
| 19 | 1454229216 |
| 20 | 2479147536 |
| 21 | 4108199481 |
| 22 | 6636929805 |
| 23 | 10479498849 |
| 24 | 16207085223 |
| 25 | 24596072424 |
| 26 | 36687908235 |
| 27 | 53862785520 |
| 28 | 77929575480 |
[0,0,27,999,11565,74811,342042,1239525,3799488, 10259640,25076952,56552364,119324403,238062357, 452774595,826245798,1454229216,2479147536, 4108199481,6636929805,10479498849,16207085223, 24596072424,36687908235,53862785520,77929575480] |