n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 23 |
3 | 106 |
4 | 473 |
5 | 1939 |
6 | 7618 |
7 | 28703 |
8 | 105112 |
9 | 375597 |
10 | 1316944 |
11 | 4544124 |
12 | 15474559 |
13 | 52108212 |
14 | 173799309 |
15 | 574908646 |
16 | 1888125243 |
17 | 6162032375 |
18 | 19998659760 |
19 | 64584817367 |
20 | 207655073310 |
21 | 665017743665 |
[1,4,23,106,473,1939,7618,28703,105112,375597, 1316944,4544124,15474559,52108212,173799309, 574908646,1888125243,6162032375,19998659760, 64584817367,207655073310,665017743665] |