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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 18 |
| 2 | 120 |
| 3 | 378 |
| 4 | 864 |
| 5 | 1650 |
| 6 | 2808 |
| 7 | 4410 |
| 8 | 6528 |
| 9 | 9234 |
| 10 | 12600 |
| 11 | 16698 |
| 12 | 21600 |
| 13 | 27378 |
| 14 | 34104 |
| 15 | 41850 |
| 16 | 50688 |
| 17 | 60690 |
| 18 | 71928 |
| 19 | 84474 |
| 20 | 98400 |
| 21 | 113778 |
| 22 | 130680 |
| 23 | 149178 |
| 24 | 169344 |
| 25 | 191250 |
| 26 | 214968 |
| 27 | 240570 |
| 28 | 268128 |
| 29 | 297714 |
| 30 | 329400 |
[0,18,120,378,864,1650,2808,4410,6528,9234,12600, 16698,21600,27378,34104,41850,50688,60690,71928, 84474,98400,113778,130680,149178,169344,191250, 214968,240570,268128,297714,329400] |