n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 3 |
3 | 12 |
4 | 40 |
5 | 143 |
6 | 497 |
7 | 1768 |
8 | 6288 |
9 | 22610 |
10 | 81686 |
11 | 297160 |
12 | 1086384 |
13 | 3991995 |
14 | 14732005 |
15 | 54587280 |
16 | 202995232 |
17 | 757398510 |
18 | 2834502346 |
19 | 10637507400 |
20 | 40023606896 |
21 | 150946230006 |
22 | 570534474698 |
23 | 2160865067312 |
24 | 8199711007200 |
[0,1,3,12,40,143,497,1768,6288,22610,81686,297160, 1086384,3991995,14732005,54587280,202995232, 757398510,2834502346,10637507400,40023606896, 150946230006,570534474698,2160865067312, 8199711007200] |