n | a(n) |
---|---|
1 | 1 |
2 | 2 |
3 | 6 |
4 | 18 |
5 | 54 |
6 | 162 |
7 | 454 |
8 | 1267 |
9 | 3613 |
10 | 10344 |
11 | 29572 |
12 | 84436 |
13 | 240868 |
14 | 686884 |
15 | 1959636 |
16 | 5592181 |
17 | 15957717 |
18 | 45533682 |
19 | 129922090 |
20 | 370708166 |
21 | 1057755082 |
22 | 3018154342 |
23 | 8611878218 |
24 | 24572725639 |
25 | 70114579881 |
26 | 200061418144 |
27 | 570845362600 |
[1,2,6,18,54,162,454,1267,3613,10344,29572,84436, 240868,686884,1959636,5592181,15957717,45533682, 129922090,370708166,1057755082,3018154342, 8611878218,24572725639,70114579881,200061418144, 570845362600] |