n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 3 |
3 | 9 |
4 | 28 |
5 | 90 |
6 | 297 |
7 | 1001 |
8 | 3431 |
9 | 11917 |
10 | 41820 |
11 | 147918 |
12 | 526309 |
13 | 1881009 |
14 | 6744843 |
15 | 24244145 |
16 | 87300092 |
17 | 314765506 |
18 | 1135980801 |
19 | 4102551897 |
20 | 14823628015 |
21 | 53581222773 |
22 | 193724727804 |
23 | 700551945014 |
24 | 2533702591613 |
25 | 9164618329825 |
26 | 33151607475987 |
27 | 119927166988761 |
[0,1,3,9,28,90,297,1001,3431,11917,41820,147918, 526309,1881009,6744843,24244145,87300092, 314765506,1135980801,4102551897,14823628015, 53581222773,193724727804,700551945014, 2533702591613,9164618329825,33151607475987, 119927166988761] |