The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 2 |
| 2 | 9 |
| 3 | 31 |
| 4 | 143 |
| 5 | 583 |
| 6 | 2713 |
| 7 | 11860 |
| 8 | 55812 |
| 9 | 252530 |
| 10 | 1199827 |
| 11 | 5542569 |
| 12 | 26520918 |
| 13 | 124245262 |
| 14 | 597677638 |
| 15 | 2828300456 |
| 16 | 13662236236 |
| 17 | 65139403991 |
| 18 | 315712785838 |
| 19 | 1514048280585 |
| 20 | 7358299247737 |
| 21 | 35451276630440 |
| 22 | 172687947421896 |
| 23 | 835112646889203 |
| 24 | 4075832518633019 |
| 25 | 19771718356983103 |
| 26 | 96658026873351532 |
[1,2,9,31,143,583,2713,11860,55812,252530,1199827, 5542569,26520918,124245262,597677638,2828300456, 13662236236,65139403991,315712785838, 1514048280585,7358299247737,35451276630440, 172687947421896,835112646889203,4075832518633019, 19771718356983103,96658026873351532] |