n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 2 |
3 | 4 |
4 | 12 |
5 | 42 |
6 | 138 |
7 | 414 |
8 | 1235 |
9 | 3764 |
10 | 11604 |
11 | 35664 |
12 | 109132 |
13 | 333652 |
14 | 1021220 |
15 | 3127709 |
16 | 9578526 |
17 | 29326904 |
18 | 89785684 |
19 | 274896606 |
20 | 841682902 |
21 | 2577075290 |
22 | 7890425175 |
23 | 24158602552 |
24 | 73968049928 |
25 | 226473538032 |
26 | 693411153800 |
27 | 2123068036904 |
28 | 6500352097064 |
[0,1,2,4,12,42,138,414,1235,3764,11604,35664, 109132,333652,1021220,3127709,9578526,29326904, 89785684,274896606,841682902,2577075290, 7890425175,24158602552,73968049928,226473538032, 693411153800,2123068036904,6500352097064] |