n | a(n) |
---|---|
1 | 1 |
2 | 4 |
3 | 15 |
4 | 57 |
5 | 220 |
6 | 859 |
7 | 3381 |
8 | 13380 |
9 | 53143 |
10 | 211585 |
11 | 843756 |
12 | 3368259 |
13 | 13455325 |
14 | 53774932 |
15 | 214978335 |
16 | 859595529 |
17 | 3437550076 |
18 | 13748021995 |
19 | 54986385093 |
20 | 219930610020 |
21 | 879683351911 |
22 | 3518631073489 |
23 | 14074256379660 |
24 | 56296324109907 |
25 | 225183460127725 |
26 | 900729032983924 |
[1,4,15,57,220,859,3381,13380,53143,211585,843756, 3368259,13455325,53774932,214978335,859595529, 3437550076,13748021995,54986385093,219930610020, 879683351911,3518631073489,14074256379660, 56296324109907,225183460127725,900729032983924] |