| n | a(n) |
|---|---|
| 1 | 2 |
| 2 | 6 |
| 3 | 43 |
| 4 | 480 |
| 5 | 11385 |
| 6 | 455509 |
| 7 | 35629548 |
| 8 | 4963103592 |
| 9 | 1301324910599 |
| 10 | 621440459491278 |
| 11 | 550719742223029437 |
| 12 | 895987628972185952650 |
| 13 | 2692063790042095644897446 |
| 14 | 14888067283069842424203964441 |
[2,6,43,480,11385,455509,35629548,4963103592, 1301324910599,621440459491278,550719742223029437, 895987628972185952650,2692063790042095644897446, 14888067283069842424203964441] |