The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 11 |
| 3 | 45 |
| 4 | 193 |
| 5 | 843 |
| 6 | 3707 |
| 7 | 16341 |
| 8 | 72097 |
| 9 | 318195 |
| 10 | 1404491 |
| 11 | 6199581 |
| 12 | 27366049 |
| 13 | 120799227 |
| 14 | 533233019 |
| 15 | 2353803525 |
| 16 | 10390190017 |
| 17 | 45864515427 |
| 18 | 202455762443 |
| 19 | 893682966669 |
| 20 | 3944907462913 |
| 21 | 17413664010795 |
| 22 | 76867631824379 |
[1,3,11,45,193,843,3707,16341,72097,318195, 1404491,6199581,27366049,120799227,533233019, 2353803525,10390190017,45864515427,202455762443, 893682966669,3944907462913,17413664010795, 76867631824379] |