| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 10 |
| 5 | 65 |
| 6 | 442 |
| 7 | 3026 |
| 8 | 20737 |
| 9 | 142130 |
| 10 | 974170 |
| 11 | 6677057 |
| 12 | 45765226 |
| 13 | 313679522 |
| 14 | 2149991425 |
| 15 | 14736260450 |
| 16 | 101003831722 |
| 17 | 692290561601 |
| 18 | 4745030099482 |
| 19 | 32522920134770 |
| 20 | 222915410843905 |
| 21 | 1527884955772562 |
| 22 | 10472279279564026 |
| 23 | 71778070001175617 |
| 24 | 491974210728665290 |
[1,1,2,10,65,442,3026,20737,142130,974170,6677057, 45765226,313679522,2149991425,14736260450, 101003831722,692290561601,4745030099482, 32522920134770,222915410843905,1527884955772562, 10472279279564026,71778070001175617, 491974210728665290] |