The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 5 |
| 8 | 17 |
| 9 | 52 |
| 10 | 150 |
| 11 | 417 |
| 12 | 1135 |
| 13 | 3047 |
| 14 | 8103 |
| 15 | 21409 |
| 16 | 56303 |
| 17 | 147569 |
| 18 | 385808 |
| 19 | 1006775 |
| 20 | 2623477 |
| 21 | 6828941 |
| 22 | 17761182 |
| 23 | 46165507 |
| 24 | 119937807 |
| 25 | 311485907 |
| 26 | 808731993 |
| 27 | 2099358057 |
| 28 | 5448906369 |
| 29 | 14141429587 |
| 30 | 36699034884 |
| 31 | 95237147804 |
| 32 | 247149109444 |
| 33 | 641388458961 |
[0,0,0,0,0,0,1,5,17,52,150,417,1135,3047,8103, 21409,56303,147569,385808,1006775,2623477,6828941, 17761182,46165507,119937807,311485907,808731993, 2099358057,5448906369,14141429587,36699034884, 95237147804,247149109444,641388458961] |