The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 7 |
| 3 | 23 |
| 4 | 89 |
| 5 | 334 |
| 6 | 1361 |
| 7 | 5438 |
| 8 | 22865 |
| 9 | 94784 |
| 10 | 407045 |
| 11 | 1728913 |
| 12 | 7538835 |
| 13 | 32581158 |
| 14 | 143720183 |
| 15 | 629266387 |
| 16 | 2801110393 |
| 17 | 12389597024 |
| 18 | 55557069245 |
| 19 | 247746634259 |
| 20 | 1117689957727 |
| 21 | 5017645126782 |
| 22 | 22752329266419 |
| 23 | 102716654869034 |
| 24 | 467793906696163 |
| 25 | 2121978774344404 |
| 26 | 9700314055341291 |
| 27 | 44183124548096243 |
[1,2,7,23,89,334,1361,5438,22865,94784,407045, 1728913,7538835,32581158,143720183,629266387, 2801110393,12389597024,55557069245,247746634259, 1117689957727,5017645126782,22752329266419, 102716654869034,467793906696163,2121978774344404, 9700314055341291,44183124548096243] |