n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 4 |
3 | 15 |
4 | 52 |
5 | 175 |
6 | 571 |
7 | 1838 |
8 | 5834 |
9 | 18363 |
10 | 57372 |
11 | 178271 |
12 | 551344 |
13 | 1698782 |
14 | 5217266 |
15 | 15979465 |
16 | 48825416 |
17 | 148877730 |
18 | 453124341 |
19 | 1376890744 |
20 | 4177819301 |
21 | 12659943750 |
22 | 38317731349 |
23 | 115851225052 |
24 | 349924919167 |
[0,1,4,15,52,175,571,1838,5834,18363,57372,178271, 551344,1698782,5217266,15979465,48825416, 148877730,453124341,1376890744,4177819301, 12659943750,38317731349,115851225052,349924919167] |