n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 15 |
3 | 56 |
4 | 211 |
5 | 798 |
6 | 3030 |
7 | 11550 |
8 | 44193 |
9 | 169652 |
10 | 653158 |
11 | 2521038 |
12 | 9752516 |
13 | 37802636 |
14 | 146792136 |
15 | 570924940 |
16 | 2223730395 |
17 | 8672669484 |
18 | 33864089798 |
19 | 132372227670 |
20 | 517947357111 |
21 | 2028479976186 |
22 | 7950990968079 |
23 | 31189593428478 |
[1,4,15,56,211,798,3030,11550,44193,169652,653158, 2521038,9752516,37802636,146792136,570924940, 2223730395,8672669484,33864089798,132372227670, 517947357111,2028479976186,7950990968079, 31189593428478] |