n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 12 |
4 | 61 |
5 | 240 |
6 | 841 |
7 | 2772 |
8 | 8821 |
9 | 27480 |
10 | 84481 |
11 | 257532 |
12 | 780781 |
13 | 2358720 |
14 | 7108921 |
15 | 21392292 |
16 | 64307941 |
17 | 193185960 |
18 | 580082161 |
19 | 1741295052 |
20 | 5225982301 |
21 | 15682141200 |
22 | 47054812201 |
23 | 141181213812 |
24 | 423577195861 |
25 | 1270798696440 |
[0,1,12,61,240,841,2772,8821,27480,84481,257532, 780781,2358720,7108921,21392292,64307941, 193185960,580082161,1741295052,5225982301, 15682141200,47054812201,141181213812,423577195861, 1270798696440] |