| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 0 |
| 9 | 0 |
| 10 | 0 |
| 11 | 0 |
| 12 | 1 |
| 13 | 0 |
| 14 | 1 |
| 15 | 1 |
| 16 | 5 |
| 17 | 8 |
| 18 | 30 |
| 19 | 85 |
| 20 | 392 |
| 21 | 1587 |
| 22 | 7659 |
| 23 | 36309 |
| 24 | 180642 |
| 25 | 899574 |
| 26 | 4541403 |
[0,0,0,0,0,0,0,0,0,0,0,1,0,1,1,5,8,30,85,392,1587, 7659,36309,180642,899574,4541403] |