The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 5 |
| 3 | 17 |
| 4 | 60 |
| 5 | 226 |
| 6 | 878 |
| 7 | 3464 |
| 8 | 14021 |
| 9 | 57807 |
| 10 | 241666 |
| 11 | 1023174 |
| 12 | 4367445 |
| 13 | 18782294 |
| 14 | 81402927 |
| 15 | 355139477 |
| 16 | 1558645747 |
| 17 | 6875471321 |
| 18 | 30454291424 |
| 19 | 135423012261 |
| 20 | 604468388810 |
| 21 | 2707499454308 |
| 22 | 12166075615983 |
| 23 | 54821229666088 |
| 24 | 247644267892085 |
| 25 | 1121332891514782 |
| 26 | 5088935535980582 |
| 27 | 23144721507136603 |
[1,2,5,17,60,226,878,3464,14021,57807,241666, 1023174,4367445,18782294,81402927,355139477, 1558645747,6875471321,30454291424,135423012261, 604468388810,2707499454308,12166075615983, 54821229666088,247644267892085,1121332891514782, 5088935535980582,23144721507136603] |