n | a(n) |
---|---|
0 | 1 |
1 | 2 |
2 | 4 |
3 | 12 |
4 | 36 |
5 | 120 |
6 | 400 |
7 | 1400 |
8 | 4900 |
9 | 17640 |
10 | 63504 |
11 | 232848 |
12 | 853776 |
13 | 3171168 |
14 | 11778624 |
15 | 44169840 |
16 | 165636900 |
17 | 625739400 |
18 | 2363904400 |
19 | 8982836720 |
20 | 34134779536 |
21 | 130332794592 |
22 | 497634306624 |
23 | 1907598175392 |
24 | 7312459672336 |
25 | 28124844893600 |
26 | 108172480360000 |
[1,2,4,12,36,120,400,1400,4900,17640,63504,232848, 853776,3171168,11778624,44169840,165636900, 625739400,2363904400,8982836720,34134779536, 130332794592,497634306624,1907598175392, 7312459672336,28124844893600,108172480360000] |