n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 4 |
3 | 15 |
4 | 50 |
5 | 161 |
6 | 504 |
7 | 1555 |
8 | 4750 |
9 | 14421 |
10 | 43604 |
11 | 131495 |
12 | 395850 |
13 | 1190281 |
14 | 3576304 |
15 | 10739835 |
16 | 32241350 |
17 | 96767741 |
18 | 290390604 |
19 | 871346575 |
20 | 2614389250 |
21 | 7843866801 |
22 | 23532998504 |
23 | 70601791715 |
24 | 211810967550 |
25 | 635444087461 |
26 | 1906354632004 |
27 | 5719108635255 |
28 | 17157415384250 |
[0,1,4,15,50,161,504,1555,4750,14421,43604,131495, 395850,1190281,3576304,10739835,32241350,96767741, 290390604,871346575,2614389250,7843866801, 23532998504,70601791715,211810967550,635444087461, 1906354632004,5719108635255,17157415384250] |