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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 6 |
| 4 | 48 |
| 5 | 204 |
| 6 | 624 |
| 7 | 1554 |
| 8 | 3360 |
| 9 | 6552 |
| 10 | 11808 |
| 11 | 19998 |
| 12 | 32208 |
| 13 | 49764 |
| 14 | 74256 |
| 15 | 107562 |
| 16 | 151872 |
| 17 | 209712 |
| 18 | 283968 |
| 19 | 377910 |
| 20 | 495216 |
| 21 | 639996 |
| 22 | 816816 |
| 23 | 1030722 |
| 24 | 1287264 |
| 25 | 1592520 |
| 26 | 1953120 |
| 27 | 2376270 |
| 28 | 2869776 |
| 29 | 3442068 |
| 30 | 4102224 |
| 31 | 4859994 |
| 32 | 5725824 |
| 33 | 6710880 |
[0,0,6,48,204,624,1554,3360,6552,11808,19998, 32208,49764,74256,107562,151872,209712,283968, 377910,495216,639996,816816,1030722,1287264, 1592520,1953120,2376270,2869776,3442068,4102224, 4859994,5725824,6710880] |