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| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 2 |
| 6 | 5 |
| 7 | 10 |
| 8 | 18 |
| 9 | 31 |
| 10 | 51 |
| 11 | 79 |
| 12 | 121 |
| 13 | 177 |
| 14 | 254 |
| 15 | 356 |
| 16 | 490 |
| 17 | 661 |
| 18 | 882 |
| 19 | 1157 |
| 20 | 1501 |
| 21 | 1926 |
| 22 | 2445 |
| 23 | 3073 |
| 24 | 3834 |
| 25 | 4740 |
[0,0,0,1,2,5,10,18,31,51,79,121,177,254,356,490, 661,882,1157,1501,1926,2445,3073,3834,4740] |