n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 4 |
4 | 7 |
5 | 22 |
6 | 160 |
7 | 938 |
8 | 7261 |
9 | 67492 |
10 | 572848 |
11 | 6774544 |
12 | 71929775 |
13 | 985400749 |
14 | 12521202682 |
15 | 188765264950 |
16 | 2889019817104 |
17 | 47703971114988 |
18 | 877662524710517 |
[0,1,4,7,22,160,938,7261,67492,572848,6774544, 71929775,985400749,12521202682,188765264950, 2889019817104,47703971114988,877662524710517] |