The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 0 |
| 2 | 11 |
| 3 | 3 |
| 4 | 23 |
| 5 | 94 |
| 6 | 255 |
| 7 | 666 |
| 8 | 2720 |
| 9 | 8571 |
| 10 | 30093 |
| 11 | 106192 |
| 12 | 369318 |
| 13 | 1291934 |
| 14 | 4552705 |
| 15 | 15952349 |
| 16 | 56078262 |
| 17 | 197277132 |
| 18 | 693611434 |
| 19 | 2438933680 |
| 20 | 8579643205 |
| 21 | 30173988847 |
| 22 | 106130105150 |
| 23 | 373307026724 |
| 24 | 1313049614295 |
| 25 | 4618497134678 |
| 26 | 16245278266932 |
[0,11,3,23,94,255,666,2720,8571,30093,106192, 369318,1291934,4552705,15952349,56078262, 197277132,693611434,2438933680,8579643205, 30173988847,106130105150,373307026724, 1313049614295,4618497134678,16245278266932] |