The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 19 |
| 5 | 49 |
| 6 | 139 |
| 7 | 379 |
| 8 | 1079 |
| 9 | 3011 |
| 10 | 8681 |
| 11 | 24641 |
| 12 | 71303 |
| 13 | 204359 |
| 14 | 594749 |
| 15 | 1717871 |
| 16 | 5012591 |
| 17 | 14552407 |
| 18 | 42601285 |
| 19 | 124209955 |
| 20 | 364300377 |
| 21 | 1065449397 |
| 22 | 3131483367 |
| 23 | 9182889013 |
| 24 | 27027421303 |
| 25 | 79418096239 |
| 26 | 234090990589 |
| 27 | 689093244919 |
| 28 | 2033346353509 |
| 29 | 5994168369289 |
| 30 | 17706646341619 |
| 31 | 52264890828619 |
[1,1,3,7,19,49,139,379,1079,3011,8681,24641,71303, 204359,594749,1717871,5012591,14552407,42601285, 124209955,364300377,1065449397,3131483367, 9182889013,27027421303,79418096239,234090990589, 689093244919,2033346353509,5994168369289, 17706646341619,52264890828619] |