n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 3 |
4 | 18 |
5 | 72 |
6 | 284 |
7 | 1047 |
8 | 3722 |
9 | 12816 |
10 | 43077 |
11 | 142046 |
12 | 461225 |
13 | 1478635 |
14 | 4689871 |
15 | 14740063 |
16 | 45963889 |
17 | 142346346 |
18 | 438168498 |
19 | 1341507977 |
20 | 4087399361 |
21 | 12399650175 |
22 | 37467705018 |
23 | 112808649521 |
24 | 338530408321 |
25 | 1012834966758 |
26 | 3021810804515 |
[0,1,3,18,72,284,1047,3722,12816,43077,142046, 461225,1478635,4689871,14740063,45963889, 142346346,438168498,1341507977,4087399361, 12399650175,37467705018,112808649521,338530408321, 1012834966758,3021810804515] |