n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 1 |
4 | 0 |
5 | 2 |
6 | 8 |
7 | 24 |
8 | 70 |
9 | 214 |
10 | 638 |
11 | 1930 |
12 | 5782 |
13 | 17394 |
14 | 52160 |
15 | 156620 |
16 | 469786 |
17 | 1409786 |
18 | 4229148 |
19 | 12688720 |
20 | 38065506 |
21 | 114200378 |
22 | 342599212 |
23 | 1027809200 |
24 | 3083421770 |
25 | 9250300098 |
26 | 27750882922 |
27 | 83252753086 |
28 | 249758206958 |
29 | 749274934114 |
30 | 2247824645796 |
31 | 6743474876960 |
[0,0,1,0,2,8,24,70,214,638,1930,5782,17394,52160, 156620,469786,1409786,4229148,12688720,38065506, 114200378,342599212,1027809200,3083421770, 9250300098,27750882922,83252753086,249758206958, 749274934114,2247824645796,6743474876960] |