n | a(n) |
---|---|
1 | 4 |
2 | -10 |
3 | 20 |
4 | -60 |
5 | 204 |
6 | -690 |
7 | 2340 |
8 | -8160 |
9 | 29120 |
10 | -104958 |
11 | 381300 |
12 | -1397740 |
13 | 5162220 |
14 | -19175130 |
15 | 71582716 |
16 | -268431360 |
17 | 1010580540 |
18 | -3817763040 |
19 | 14467258260 |
20 | -54975528948 |
21 | 209430785460 |
22 | -799645010850 |
23 | 3059510616420 |
[4,-10,20,-60,204,-690,2340,-8160,29120,-104958, 381300,-1397740,5162220,-19175130,71582716, -268431360,1010580540,-3817763040,14467258260, -54975528948,209430785460,-799645010850, 3059510616420] |