n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 4 |
3 | 18 |
4 | 128 |
5 | 1404 |
6 | 18261 |
7 | 310346 |
8 | 5896727 |
9 | 135624239 |
10 | 3933101823 |
11 | 121926157640 |
12 | 4511267827531 |
13 | 184961980943492 |
14 | 7953365180610400 |
[0,1,4,18,128,1404,18261,310346,5896727,135624239, 3933101823,121926157640,4511267827531, 184961980943492,7953365180610400] |