n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 3 |
4 | 10 |
5 | 30 |
6 | 90 |
7 | 270 |
8 | 810 |
9 | 2430 |
10 | 7290 |
11 | 21870 |
12 | 65610 |
13 | 196830 |
14 | 590490 |
15 | 1771470 |
16 | 5314410 |
17 | 15943230 |
18 | 47829690 |
19 | 143489070 |
20 | 430467210 |
21 | 1291401630 |
22 | 3874204890 |
23 | 11622614670 |
24 | 34867844010 |
25 | 104603532030 |
26 | 313810596090 |
27 | 941431788270 |
[0,1,3,10,30,90,270,810,2430,7290,21870,65610, 196830,590490,1771470,5314410,15943230,47829690, 143489070,430467210,1291401630,3874204890, 11622614670,34867844010,104603532030,313810596090, 941431788270] |