The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 48 |
| 5 | 259 |
| 6 | 1387 |
| 7 | 7099 |
| 8 | 34847 |
| 9 | 163588 |
| 10 | 737538 |
| 11 | 3200055 |
| 12 | 13400036 |
| 13 | 54289217 |
| 14 | 213301597 |
| 15 | 814463579 |
| 16 | 3028171125 |
| 17 | 10981909481 |
| 18 | 38908787433 |
| 19 | 134868584027 |
| 20 | 457962911722 |
| 21 | 1525173224446 |
| 22 | 4987066348804 |
| 23 | 16026405323579 |
| 24 | 50662230359800 |
[1,3,9,48,259,1387,7099,34847,163588,737538, 3200055,13400036,54289217,213301597,814463579, 3028171125,10981909481,38908787433,134868584027, 457962911722,1525173224446,4987066348804, 16026405323579,50662230359800] |