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| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 1 |
| 3 | 3 |
| 4 | 6 |
| 5 | 12 |
| 6 | 27 |
| 7 | 63 |
| 8 | 144 |
| 9 | 324 |
| 10 | 729 |
| 11 | 1647 |
| 12 | 3726 |
| 13 | 8424 |
| 14 | 19035 |
| 15 | 43011 |
| 16 | 97200 |
| 17 | 219672 |
| 18 | 496449 |
| 19 | 1121931 |
| 20 | 2535462 |
| 21 | 5729940 |
| 22 | 12949227 |
| 23 | 29264247 |
| 24 | 66134880 |
| 25 | 149459580 |
| 26 | 337766841 |
| 27 | 763326423 |
| 28 | 1725057486 |
| 29 | 3898493712 |
| 30 | 8810287947 |
| 31 | 19910555163 |
[0,0,1,3,6,12,27,63,144,324,729,1647,3726,8424, 19035,43011,97200,219672,496449,1121931,2535462, 5729940,12949227,29264247,66134880,149459580, 337766841,763326423,1725057486,3898493712, 8810287947,19910555163] |