The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 7 |
| 5 | 5 |
| 6 | 43 |
| 7 | 43 |
| 8 | 275 |
| 9 | 371 |
| 10 | 1913 |
| 11 | 3017 |
| 12 | 14305 |
| 13 | 25039 |
| 14 | 109803 |
| 15 | 212645 |
| 16 | 866361 |
| 17 | 1818147 |
| 18 | 6992905 |
| 19 | 15653093 |
| 20 | 57383555 |
| 21 | 135498383 |
| 22 | 477220531 |
| 23 | 1177254905 |
| 24 | 4012238901 |
| 25 | 10256656225 |
| 26 | 34031432595 |
| 27 | 89553075529 |
| 28 | 290731277941 |
[0,1,1,7,5,43,43,275,371,1913,3017,14305,25039, 109803,212645,866361,1818147,6992905,15653093, 57383555,135498383,477220531,1177254905, 4012238901,10256656225,34031432595,89553075529, 290731277941] |