The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 3 |
| 2 | 7 |
| 3 | 17 |
| 4 | 101 |
| 5 | 426 |
| 6 | 1722 |
| 7 | 8483 |
| 8 | 46788 |
| 9 | 246899 |
| 10 | 1263032 |
| 11 | 6568737 |
| 12 | 34802586 |
| 13 | 184657217 |
| 14 | 976867173 |
| 15 | 5178449568 |
| 16 | 27557967928 |
| 17 | 146974586179 |
| 18 | 784645686795 |
| 19 | 4194027064034 |
| 20 | 22450449919571 |
| 21 | 120330101083792 |
| 22 | 645608703621958 |
[3,7,17,101,426,1722,8483,46788,246899,1263032, 6568737,34802586,184657217,976867173,5178449568, 27557967928,146974586179,784645686795, 4194027064034,22450449919571,120330101083792, 645608703621958] |