The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 6 |
| 3 | 43 |
| 4 | 352 |
| 5 | 2456 |
| 6 | 16629 |
| 7 | 118863 |
| 8 | 863435 |
| 9 | 6296517 |
| 10 | 46082534 |
| 11 | 337974465 |
| 12 | 2482292322 |
| 13 | 18247326003 |
| 14 | 134198700821 |
| 15 | 987225183085 |
| 16 | 7263640120506 |
| 17 | 53448292499747 |
| 18 | 393312676324283 |
| 19 | 2894385928048833 |
| 20 | 21300183245716512 |
[1,6,43,352,2456,16629,118863,863435,6296517, 46082534,337974465,2482292322,18247326003, 134198700821,987225183085,7263640120506, 53448292499747,393312676324283,2894385928048833, 21300183245716512] |