n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 0 |
3 | 1 |
4 | 2 |
5 | 6 |
6 | 16 |
7 | 43 |
8 | 117 |
9 | 319 |
10 | 875 |
11 | 2409 |
12 | 6692 |
13 | 18614 |
14 | 52099 |
15 | 146186 |
16 | 411720 |
17 | 1162295 |
18 | 3289994 |
19 | 9330913 |
20 | 26517036 |
21 | 75481622 |
22 | 215201178 |
23 | 614398459 |
24 | 1756392061 |
25 | 5026955216 |
26 | 14403488345 |
27 | 41311616835 |
28 | 118601561506 |
29 | 340795908579 |
30 | 980078195995 |
[0,0,0,1,2,6,16,43,117,319,875,2409,6692,18614, 52099,146186,411720,1162295,3289994,9330913, 26517036,75481622,215201178,614398459,1756392061, 5026955216,14403488345,41311616835,118601561506, 340795908579,980078195995] |