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| n | a(n) |
|---|---|
| -1 | 1 |
| 0 | 0 |
| 1 | 6 |
| 2 | 6 |
| 3 | 15 |
| 4 | 30 |
| 5 | 41 |
| 6 | 66 |
| 7 | 111 |
| 8 | 146 |
| 9 | 222 |
| 10 | 336 |
| 11 | 463 |
| 12 | 642 |
| 13 | 942 |
| 14 | 1238 |
| 15 | 1698 |
| 16 | 2334 |
| 17 | 3090 |
| 18 | 4098 |
| 19 | 5514 |
| 20 | 7136 |
| 21 | 9336 |
| 22 | 12216 |
| 23 | 15673 |
| 24 | 20142 |
| 25 | 26013 |
| 26 | 32880 |
| 27 | 41820 |
| 28 | 53070 |
| 29 | 66609 |
| 30 | 83568 |
| 31 | 105039 |
| 32 | 130482 |
| 33 | 162321 |
| 34 | 201708 |
| 35 | 248802 |
| 36 | 306642 |
| 37 | 377955 |
| 38 | 462596 |
| 39 | 566223 |
| 40 | 692064 |
[1,0,6,6,15,30,41,66,111,146,222,336,463,642,942, 1238,1698,2334,3090,4098,5514,7136,9336,12216, 15673,20142,26013,32880,41820,53070,66609,83568, 105039,130482,162321,201708,248802,306642,377955, 462596,566223,692064] |