n | a(n) |
---|---|
0 | 2 |
1 | 0 |
2 | 1 |
3 | 2 |
4 | 9 |
5 | 40 |
6 | 214 |
7 | 1355 |
8 | 9940 |
9 | 82834 |
10 | 773118 |
11 | 7988887 |
12 | 90540729 |
13 | 1116669003 |
14 | 14888920041 |
15 | 213407853922 |
16 | 3272253760146 |
17 | 53446811415729 |
18 | 926411397872639 |
19 | 16984208960998389 |
20 | 328361373245968867 |
[2,0,1,2,9,40,214,1355,9940,82834,773118,7988887, 90540729,1116669003,14888920041,213407853922, 3272253760146,53446811415729,926411397872639, 16984208960998389,328361373245968867] |