The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 2 |
| 4 | 38 |
| 5 | 236 |
| 6 | 850 |
| 7 | 1000 |
| 8 | 26840 |
| 9 | 477368 |
| 10 | 47036 |
| 11 | 22339372 |
| 12 | 73096731 |
| 13 | 260586441 |
| 14 | 1180973647 |
| 15 | 3853501438 |
| 16 | 178350939014 |
| 17 | 1261487067476 |
| 18 | 3639250753600 |
| 19 | 26083459413092 |
| 20 | 946868742489918 |
| 21 | 264892551871161 |
| 22 | 5030764357055773 |
[1,2,2,38,236,850,1000,26840,477368,47036, 22339372,73096731,260586441,1180973647,3853501438, 178350939014,1261487067476,3639250753600, 26083459413092,946868742489918,264892551871161, 5030764357055773] |