The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 5 |
| 2 | 40 |
| 3 | 328 |
| 4 | 2556 |
| 5 | 18452 |
| 6 | 126096 |
| 7 | 827901 |
| 8 | 5276913 |
| 9 | 32887213 |
| 10 | 201443165 |
| 11 | 1217389949 |
| 12 | 7279826998 |
| 13 | 43168558912 |
| 14 | 254258462459 |
| 15 | 1489291941733 |
| 16 | 8683388113017 |
| 17 | 50433408838966 |
[1,5,40,328,2556,18452,126096,827901,5276913, 32887213,201443165,1217389949,7279826998, 43168558912,254258462459,1489291941733, 8683388113017,50433408838966] |