n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 1 |
4 | 1 |
5 | 2 |
6 | 5 |
7 | 12 |
8 | 31 |
9 | 90 |
10 | 285 |
11 | 938 |
12 | 3285 |
13 | 11983 |
14 | 45390 |
15 | 177803 |
16 | 718390 |
17 | 2986407 |
18 | 12749364 |
19 | 55802982 |
20 | 250068732 |
21 | 1145923828 |
22 | 5363795830 |
23 | 25620207380 |
24 | 124767647097 |
25 | 618983876918 |
26 | 3126035142910 |
27 | 16060182735947 |
28 | 83883575376862 |
29 | 445164927249466 |
30 | 2399098651337048 |
[0,0,1,1,2,5,12,31,90,285,938,3285,11983,45390, 177803,718390,2986407,12749364,55802982,250068732, 1145923828,5363795830,25620207380,124767647097, 618983876918,3126035142910,16060182735947, 83883575376862,445164927249466,2399098651337048] |