n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 16 |
4 | 60 |
5 | 231 |
6 | 920 |
7 | 3819 |
8 | 16365 |
9 | 71792 |
10 | 320219 |
11 | 1446517 |
12 | 6602975 |
13 | 30415725 |
14 | 141231704 |
15 | 660431602 |
16 | 3107519738 |
17 | 14701758926 |
18 | 69891556656 |
19 | 333700223891 |
20 | 1599475107712 |
21 | 7693580712200 |
22 | 37125486197570 |
23 | 179675330190428 |
24 | 871910824853956 |
25 | 4241603521253775 |
[1,1,4,16,60,231,920,3819,16365,71792,320219, 1446517,6602975,30415725,141231704,660431602, 3107519738,14701758926,69891556656,333700223891, 1599475107712,7693580712200,37125486197570, 179675330190428,871910824853956,4241603521253775] |