n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 4 |
4 | 24 |
5 | 128 |
6 | 704 |
7 | 3840 |
8 | 20992 |
9 | 114688 |
10 | 626688 |
11 | 3424256 |
12 | 18710528 |
13 | 102236160 |
14 | 558628864 |
15 | 3052404736 |
16 | 16678649856 |
17 | 91133837312 |
18 | 497964548096 |
19 | 2720928890880 |
20 | 14867431948288 |
21 | 81237158920192 |
22 | 443888091267072 |
23 | 2425449636429824 |
24 | 13252903275855872 |
[0,1,4,24,128,704,3840,20992,114688,626688, 3424256,18710528,102236160,558628864,3052404736, 16678649856,91133837312,497964548096, 2720928890880,14867431948288,81237158920192, 443888091267072,2425449636429824, 13252903275855872] |