n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 1 |
4 | 1 |
5 | 4 |
6 | 13 |
7 | 36 |
8 | 90 |
9 | 243 |
10 | 661 |
11 | 1804 |
12 | 4914 |
13 | 13608 |
14 | 37944 |
15 | 106288 |
16 | 298755 |
17 | 843796 |
18 | 2391363 |
19 | 6797196 |
20 | 19370696 |
21 | 55345784 |
22 | 158491993 |
23 | 454803100 |
24 | 1307541690 |
25 | 3765720066 |
26 | 10862667648 |
27 | 31381059609 |
28 | 90780846494 |
29 | 262951527460 |
[0,0,1,1,4,13,36,90,243,661,1804,4914,13608,37944, 106288,298755,843796,2391363,6797196,19370696, 55345784,158491993,454803100,1307541690, 3765720066,10862667648,31381059609,90780846494, 262951527460] |