| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 1 |
| 6 | 5 |
| 7 | 9 |
| 8 | 29 |
| 9 | 62 |
| 10 | 181 |
| 11 | 422 |
| 12 | 1166 |
| 13 | 2885 |
| 14 | 7788 |
| 15 | 19893 |
| 16 | 53319 |
| 17 | 138931 |
| 18 | 372027 |
| 19 | 982379 |
| 20 | 2635898 |
| 21 | 7026483 |
| 22 | 18914903 |
| 23 | 50781803 |
| 24 | 137201419 |
| 25 | 370442111 |
| 26 | 1004512375 |
| 27 | 2724867782 |
| 28 | 7414635185 |
| 29 | 20193165834 |
| 30 | 55125632502 |
[0,0,0,1,1,5,9,29,62,181,422,1166,2885,7788,19893, 53319,138931,372027,982379,2635898,7026483, 18914903,50781803,137201419,370442111,1004512375, 2724867782,7414635185,20193165834,55125632502] |