n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 4 |
3 | 4 |
4 | 40 |
5 | 72 |
6 | 428 |
7 | 1036 |
8 | 4816 |
9 | 13712 |
10 | 56020 |
11 | 174612 |
12 | 665080 |
13 | 2180568 |
14 | 7991676 |
15 | 26951708 |
16 | 96696224 |
17 | 331269920 |
18 | 1174584228 |
19 | 4059317284 |
20 | 14299305416 |
21 | 49658576744 |
22 | 174293008204 |
23 | 606920893484 |
24 | 2125899390576 |
25 | 7413894423728 |
26 | 25940068045428 |
27 | 90539218468404 |
[0,0,4,4,40,72,428,1036,4816,13712,56020,174612, 665080,2180568,7991676,26951708,96696224, 331269920,1174584228,4059317284,14299305416, 49658576744,174293008204,606920893484, 2125899390576,7413894423728,25940068045428, 90539218468404] |