n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 1 |
4 | 4 |
5 | 14 |
6 | 45 |
7 | 140 |
8 | 424 |
9 | 1269 |
10 | 3760 |
11 | 11080 |
12 | 32517 |
13 | 95190 |
14 | 278154 |
15 | 811887 |
16 | 2367973 |
17 | 6903453 |
18 | 20120905 |
19 | 58639016 |
20 | 170894228 |
21 | 498084608 |
22 | 1451899005 |
23 | 4232957241 |
24 | 12343454790 |
25 | 36001675800 |
26 | 105028397290 |
27 | 306472665459 |
28 | 894497511566 |
[0,0,1,4,14,45,140,424,1269,3760,11080,32517, 95190,278154,811887,2367973,6903453,20120905, 58639016,170894228,498084608,1451899005, 4232957241,12343454790,36001675800,105028397290, 306472665459,894497511566] |