n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 12 |
4 | 45 |
5 | 171 |
6 | 687 |
7 | 2803 |
8 | 11748 |
9 | 49831 |
10 | 214434 |
11 | 931716 |
12 | 4085156 |
13 | 18040522 |
14 | 80183435 |
15 | 358314337 |
16 | 1608920279 |
17 | 7254733913 |
18 | 32835218026 |
19 | 149109378700 |
20 | 679164584418 |
21 | 3101883535311 |
22 | 14201896280766 |
23 | 65169414956550 |
24 | 299665789841870 |
25 | 1380552538613722 |
26 | 6371296684194483 |
27 | 29451369951867444 |
[1,1,4,12,45,171,687,2803,11748,49831,214434, 931716,4085156,18040522,80183435,358314337, 1608920279,7254733913,32835218026,149109378700, 679164584418,3101883535311,14201896280766, 65169414956550,299665789841870,1380552538613722, 6371296684194483,29451369951867444] |