n | a(n) |
---|---|
0 | 0 |
1 | 2 |
2 | 6 |
3 | 12 |
4 | 24 |
5 | 40 |
6 | 72 |
7 | 126 |
8 | 240 |
9 | 459 |
10 | 940 |
11 | 1936 |
12 | 4104 |
13 | 8671 |
14 | 18508 |
15 | 39300 |
16 | 83616 |
17 | 177055 |
18 | 374652 |
19 | 789811 |
20 | 1662400 |
21 | 3488877 |
22 | 7309588 |
23 | 15279406 |
24 | 31886928 |
25 | 66422275 |
26 | 138157708 |
27 | 286924599 |
28 | 595102144 |
29 | 1232672869 |
[0,2,6,12,24,40,72,126,240,459,940,1936,4104,8671, 18508,39300,83616,177055,374652,789811,1662400, 3488877,7309588,15279406,31886928,66422275, 138157708,286924599,595102144,1232672869] |