n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 4 |
3 | 27 |
4 | 152 |
5 | 905 |
6 | 5292 |
7 | 31123 |
8 | 182704 |
9 | 1073169 |
10 | 6302420 |
11 | 37014539 |
12 | 217384776 |
13 | 1276699033 |
14 | 7498028668 |
15 | 44035804035 |
16 | 258621531488 |
17 | 1518879970337 |
18 | 8920356727716 |
19 | 52389106584571 |
20 | 307680350343160 |
[0,1,4,27,152,905,5292,31123,182704,1073169, 6302420,37014539,217384776,1276699033,7498028668, 44035804035,258621531488,1518879970337, 8920356727716,52389106584571,307680350343160] |