The OEIS is supported by the many generous donors to the OEIS Foundation.
| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 8 |
| 3 | 70 |
| 4 | 649 |
| 5 | 8264 |
| 6 | 121368 |
| 7 | 2195114 |
| 8 | 55665676 |
| 9 | 2065512284 |
| 10 | 105764508137 |
| 11 | 7817598459732 |
| 12 | 873942008386780 |
| 13 | 140850901178992246 |
[1,8,70,649,8264,121368,2195114,55665676, 2065512284,105764508137,7817598459732, 873942008386780,140850901178992246] |