n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 4 |
4 | 16 |
5 | 54 |
6 | 178 |
7 | 565 |
8 | 1770 |
9 | 5493 |
10 | 16927 |
11 | 51901 |
12 | 158533 |
13 | 482802 |
14 | 1466859 |
15 | 4448104 |
16 | 13467249 |
17 | 40720970 |
18 | 122994566 |
19 | 371156622 |
20 | 1119161662 |
21 | 3372427789 |
22 | 10156591942 |
23 | 30573367574 |
24 | 91993546765 |
25 | 276703494365 |
26 | 832023918335 |
27 | 2501142914874 |
28 | 7516883840470 |
[0,1,4,16,54,178,565,1770,5493,16927,51901,158533, 482802,1466859,4448104,13467249,40720970, 122994566,371156622,1119161662,3372427789, 10156591942,30573367574,91993546765,276703494365, 832023918335,2501142914874,7516883840470] |