The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 0 |
| 1 | 1 |
| 2 | 5 |
| 3 | 17 |
| 4 | 53 |
| 5 | 147 |
| 6 | 389 |
| 7 | 981 |
| 8 | 2401 |
| 9 | 5697 |
| 10 | 13293 |
| 11 | 30423 |
| 12 | 68745 |
| 13 | 153403 |
| 14 | 339195 |
| 15 | 743169 |
| 16 | 1617857 |
| 17 | 3497875 |
| 18 | 7523697 |
| 19 | 16102889 |
| 20 | 34324847 |
| 21 | 72875031 |
| 22 | 154233691 |
| 23 | 325388121 |
| 24 | 684664081 |
| 25 | 1436991619 |
| 26 | 3009410483 |
| 27 | 6289146455 |
| 28 | 13119434889 |
| 29 | 27319198507 |
| 30 | 56799400255 |
| 31 | 117916622547 |
[0,1,5,17,53,147,389,981,2401,5697,13293,30423, 68745,153403,339195,743169,1617857,3497875, 7523697,16102889,34324847,72875031,154233691, 325388121,684664081,1436991619,3009410483, 6289146455,13119434889,27319198507,56799400255, 117916622547] |