n | a(n) |
---|---|
1 | 1 |
2 | 1 |
3 | 2 |
4 | 6 |
5 | 20 |
6 | 71 |
7 | 263 |
8 | 1005 |
9 | 3933 |
10 | 15684 |
11 | 63505 |
12 | 260390 |
13 | 1079019 |
14 | 4511700 |
15 | 19011521 |
16 | 80653480 |
17 | 344193353 |
18 | 1476589475 |
19 | 6364258163 |
20 | 27545933212 |
21 | 119676949397 |
22 | 521739175908 |
23 | 2281673067934 |
24 | 10006784399183 |
25 | 44002280467770 |
26 | 193957104163645 |
27 | 856853526774173 |
[1,1,2,6,20,71,263,1005,3933,15684,63505,260390, 1079019,4511700,19011521,80653480,344193353, 1476589475,6364258163,27545933212,119676949397, 521739175908,2281673067934,10006784399183, 44002280467770,193957104163645,856853526774173] |