n | a(n) |
---|---|
2 | 1 |
3 | 2 |
4 | 6 |
5 | 20 |
6 | 64 |
7 | 204 |
8 | 656 |
9 | 2120 |
10 | 6873 |
11 | 22350 |
12 | 72881 |
13 | 238232 |
14 | 780384 |
15 | 2561164 |
16 | 8419766 |
17 | 27721784 |
18 | 91397927 |
19 | 301710074 |
20 | 997087170 |
21 | 3298556716 |
22 | 10922576840 |
23 | 36199599880 |
24 | 120068987717 |
25 | 398547827336 |
26 | 1323821438203 |
27 | 4400043488826 |
28 | 14633372199291 |
[1,2,6,20,64,204,656,2120,6873,22350,72881,238232, 780384,2561164,8419766,27721784,91397927, 301710074,997087170,3298556716,10922576840, 36199599880,120068987717,398547827336, 1323821438203,4400043488826,14633372199291] |