| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 14 |
| 3 | 86 |
| 4 | 648 |
| 5 | 5752 |
| 6 | 58576 |
| 7 | 671568 |
| 8 | 8546432 |
| 9 | 119401856 |
| 10 | 1815177984 |
| 11 | 29808908032 |
| 12 | 525586164736 |
| 13 | 9898343691264 |
| 14 | 198227905206272 |
| 15 | 4204989697906688 |
| 16 | 94163381359509504 |
| 17 | 2219240984918720512 |
| 18 | 54898699229094412288 |
| 19 | 1422015190821016633344 |
| 20 | 38484192401958599131136 |
[1,3,14,86,648,5752,58576,671568,8546432, 119401856,1815177984,29808908032,525586164736, 9898343691264,198227905206272,4204989697906688, 94163381359509504,2219240984918720512, 54898699229094412288,1422015190821016633344, 38484192401958599131136] |