n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 9 |
3 | 36 |
4 | 140 |
5 | 481 |
6 | 1774 |
7 | 5925 |
8 | 20076 |
9 | 64980 |
10 | 208486 |
11 | 652058 |
12 | 2017023 |
13 | 6117878 |
14 | 18347256 |
15 | 54222195 |
16 | 158463794 |
17 | 457570786 |
18 | 1307951914 |
19 | 3700153918 |
20 | 10371860026 |
21 | 28810051738 |
22 | 79359812567 |
23 | 216834266612 |
24 | 587961817595 |
25 | 1582612248239 |
26 | 4230325722508 |
[1,1,9,36,140,481,1774,5925,20076,64980,208486, 652058,2017023,6117878,18347256,54222195, 158463794,457570786,1307951914,3700153918, 10371860026,28810051738,79359812567,216834266612, 587961817595,1582612248239,4230325722508] |