n | a(n) |
---|---|
3 | 0 |
4 | 1 |
5 | 4 |
6 | 4 |
7 | 12 |
8 | 21 |
9 | 36 |
10 | 81 |
11 | 215 |
12 | 498 |
13 | 1230 |
14 | 3024 |
15 | 7518 |
16 | 18716 |
17 | 47494 |
18 | 119818 |
19 | 305638 |
20 | 781495 |
21 | 2015124 |
22 | 5200150 |
23 | 13532475 |
24 | 35199561 |
25 | 92135477 |
26 | 241342171 |
27 | 634477759 |
28 | 1670301161 |
29 | 4410053106 |
30 | 11656356800 |
31 | 30891424869 |
[0,1,4,4,12,21,36,81,215,498,1230,3024,7518,18716, 47494,119818,305638,781495,2015124,5200150, 13532475,35199561,92135477,241342171,634477759, 1670301161,4410053106,11656356800,30891424869] |