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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 9 |
| 3 | 40 |
| 4 | 120 |
| 5 | 280 |
| 6 | 552 |
| 7 | 968 |
| 8 | 1560 |
| 9 | 2360 |
| 10 | 3400 |
| 11 | 4712 |
| 12 | 6328 |
| 13 | 8280 |
| 14 | 10600 |
| 15 | 13320 |
| 16 | 16472 |
| 17 | 20088 |
| 18 | 24200 |
| 19 | 28840 |
| 20 | 34040 |
| 21 | 39832 |
| 22 | 46248 |
| 23 | 53320 |
| 24 | 61080 |
| 25 | 69560 |
| 26 | 78792 |
| 27 | 88808 |
| 28 | 99640 |
| 29 | 111320 |
| 30 | 123880 |
| 31 | 137352 |
| 32 | 151768 |
| 33 | 167160 |
| 34 | 183560 |
| 35 | 201000 |
| 36 | 219512 |
| 37 | 239128 |
| 38 | 259880 |
| 39 | 281800 |
[0,1,9,40,120,280,552,968,1560,2360,3400,4712, 6328,8280,10600,13320,16472,20088,24200,28840, 34040,39832,46248,53320,61080,69560,78792,88808, 99640,111320,123880,137352,151768,167160,183560, 201000,219512,239128,259880,281800] |