n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 1 |
3 | 0 |
4 | 3 |
5 | 1 |
6 | 15 |
7 | 21 |
8 | 106 |
9 | 378 |
10 | 1116 |
11 | 6931 |
12 | 20196 |
13 | 136500 |
14 | 558559 |
15 | 3103191 |
16 | 18524418 |
17 | 90852217 |
18 | 661904622 |
19 | 3569749659 |
20 | 25657118047 |
21 | 171935108541 |
22 | 1149965503347 |
23 | 9166884110308 |
24 | 62758177512570 |
25 | 525194926694256 |
26 | 4072360499426311 |
27 | 33295056117878646 |
[1,0,1,0,3,1,15,21,106,378,1116,6931,20196,136500, 558559,3103191,18524418,90852217,661904622, 3569749659,25657118047,171935108541,1149965503347, 9166884110308,62758177512570,525194926694256, 4072360499426311,33295056117878646] |