n | a(n) |
---|---|
1 | 0 |
2 | 2 |
3 | 6 |
4 | 12 |
5 | 30 |
6 | 90 |
7 | 252 |
8 | 702 |
9 | 2106 |
10 | 6480 |
11 | 19602 |
12 | 58806 |
13 | 176904 |
14 | 532170 |
15 | 1596510 |
16 | 4785156 |
17 | 14351094 |
18 | 43053282 |
19 | 129146724 |
20 | 387400806 |
21 | 1162202418 |
22 | 3486725352 |
23 | 10460294154 |
24 | 31380882462 |
25 | 94143001680 |
26 | 282430067922 |
27 | 847290203766 |
28 | 2541867422652 |
29 | 7625599079310 |
[0,2,6,12,30,90,252,702,2106,6480,19602,58806, 176904,532170,1596510,4785156,14351094,43053282, 129146724,387400806,1162202418,3486725352, 10460294154,31380882462,94143001680,282430067922, 847290203766,2541867422652,7625599079310] |