The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 48 |
| 5 | 247 |
| 6 | 1448 |
| 7 | 9445 |
| 8 | 67651 |
| 9 | 526704 |
| 10 | 4418875 |
| 11 | 39670270 |
| 12 | 378931567 |
| 13 | 3832882393 |
| 14 | 40886570975 |
| 15 | 458341921775 |
| 16 | 5382862509572 |
| 17 | 66050096110691 |
| 18 | 844741961321026 |
| 19 | 11236481306649167 |
| 20 | 155150031880549077 |
| 21 | 2219877203279634396 |
| 22 | 32860282502526114729 |
[1,1,3,11,48,247,1448,9445,67651,526704,4418875, 39670270,378931567,3832882393,40886570975, 458341921775,5382862509572,66050096110691, 844741961321026,11236481306649167, 155150031880549077,2219877203279634396, 32860282502526114729] |