The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 6 |
| 4 | 12 |
| 5 | 20 |
| 6 | 36 |
| 7 | 46 |
| 8 | 66 |
| 9 | 90 |
| 10 | 138 |
| 11 | 216 |
| 12 | 378 |
| 13 | 459 |
| 14 | 616 |
| 15 | 873 |
| 16 | 1645 |
| 17 | 2133 |
[0,1,3,6,12,20,36,46,66,90,138,216,378,459,616, 873,1645,2133] |