| n | a(n) |
|---|---|
| 1 | 28 |
| 2 | 160 |
| 3 | 918 |
| 4 | 5430 |
| 5 | 32042 |
| 6 | 188394 |
| 7 | 1107926 |
| 8 | 6519094 |
| 9 | 38356642 |
| 10 | 225665454 |
| 11 | 1327676850 |
| 12 | 7811308282 |
| 13 | 45957316482 |
| 14 | 270386512686 |
| 15 | 1590799536334 |
| 16 | 9359355830962 |
| 17 | 55065102381718 |
| 18 | 323971594861746 |
| 19 | 1906063733817962 |
[28,160,918,5430,32042,188394,1107926,6519094, 38356642,225665454,1327676850,7811308282, 45957316482,270386512686,1590799536334, 9359355830962,55065102381718,323971594861746, 1906063733817962] |
