n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 4 |
4 | 7 |
5 | 20 |
6 | 43 |
7 | 110 |
8 | 262 |
9 | 674 |
10 | 1684 |
11 | 4397 |
12 | 11320 |
13 | 29938 |
14 | 78641 |
15 | 210044 |
16 | 559724 |
17 | 1507563 |
18 | 4060585 |
19 | 11016027 |
20 | 29919220 |
21 | 81673846 |
22 | 223307300 |
23 | 612851316 |
24 | 1684816018 |
25 | 4645243490 |
26 | 12829177587 |
27 | 35513736868 |
28 | 98465916370 |
29 | 273531234027 |
30 | 760966444416 |
[1,1,1,4,7,20,43,110,262,674,1684,4397,11320, 29938,78641,210044,559724,1507563,4060585, 11016027,29919220,81673846,223307300,612851316, 1684816018,4645243490,12829177587,35513736868, 98465916370,273531234027,760966444416] |