The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 139 |
| 3 | 1627 |
| 4 | 18839 |
| 5 | 123229 |
| 6 | 776257 |
| 7 | 3873011 |
| 8 | 23884639 |
| 9 | 36539311 |
| 10 | 196943081 |
| 11 | 452942827 |
| 12 | 73712513057 |
| 13 | 154351758091 |
| 14 | 154351758091 |
| 15 | 4010803176619 |
| 16 | 6987191424553 |
| 17 | 71894236537009 |
| 18 | 196948379177587 |
| 19 | 253931039382791 |
[2,139,1627,18839,123229,776257,3873011,23884639, 36539311,196943081,452942827,73712513057, 154351758091,154351758091,4010803176619, 6987191424553,71894236537009,196948379177587, 253931039382791] |