| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 7 |
| 3 | 40 |
| 4 | 345 |
| 5 | 3226 |
| 6 | 38503 |
| 7 | 529614 |
| 8 | 8219025 |
| 9 | 141633028 |
| 10 | 2677676931 |
| 11 | 55021969234 |
| 12 | 1219667932585 |
| 13 | 28986449652564 |
| 14 | 734758590703803 |
| 15 | 19777243624646566 |
| 16 | 563105619051710817 |
| 17 | 16902630001714260832 |
| 18 | 533291777845757001523 |
| 19 | 17638752528002502032130 |
| 20 | 610137644831701323189321 |
[1,7,40,345,3226,38503,529614,8219025,141633028, 2677676931,55021969234,1219667932585, 28986449652564,734758590703803,19777243624646566, 563105619051710817,16902630001714260832, 533291777845757001523,17638752528002502032130, 610137644831701323189321] |