n | a(n) |
---|---|
0 | 0 |
1 | 0 |
2 | 1 |
3 | 3 |
4 | 6 |
5 | 15 |
6 | 26 |
7 | 57 |
8 | 118 |
9 | 237 |
10 | 486 |
11 | 989 |
12 | 1992 |
13 | 3997 |
14 | 8038 |
15 | 16133 |
16 | 32331 |
17 | 64777 |
18 | 129810 |
19 | 260191 |
20 | 521325 |
21 | 1043924 |
22 | 2089305 |
23 | 4180716 |
[0,0,1,3,6,15,26,57,118,237,486,989,1992,3997, 8038,16133,32331,64777,129810,260191,521325, 1043924,2089305,4180716] |