n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 2 |
3 | 7 |
4 | 20 |
5 | 58 |
6 | 174 |
7 | 519 |
8 | 1550 |
9 | 4634 |
10 | 13884 |
11 | 41616 |
12 | 124824 |
13 | 374390 |
14 | 1123288 |
15 | 3369297 |
16 | 10107324 |
17 | 30320434 |
18 | 90961626 |
19 | 272878138 |
20 | 818632094 |
21 | 2455888346 |
22 | 7367661682 |
23 | 22102935920 |
24 | 66308767426 |
25 | 198926187730 |
26 | 596778527246 |
27 | 1790335274112 |
28 | 5371006016314 |
[1,1,2,7,20,58,174,519,1550,4634,13884,41616, 124824,374390,1123288,3369297,10107324,30320434, 90961626,272878138,818632094,2455888346, 7367661682,22102935920,66308767426,198926187730, 596778527246,1790335274112,5371006016314] |