n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 0 |
3 | 2 |
4 | 4 |
5 | 13 |
6 | 40 |
7 | 130 |
8 | 432 |
9 | 1466 |
10 | 5056 |
11 | 17672 |
12 | 62460 |
13 | 222853 |
14 | 801592 |
15 | 2903626 |
16 | 10582816 |
17 | 38781310 |
18 | 142805056 |
19 | 528134764 |
20 | 1960825672 |
21 | 7305767602 |
22 | 27307800400 |
23 | 102371942932 |
24 | 384806950624 |
25 | 1450038737668 |
26 | 5476570993440 |
27 | 20727983587220 |
28 | 78606637060012 |
[0,1,0,2,4,13,40,130,432,1466,5056,17672,62460, 222853,801592,2903626,10582816,38781310,142805056, 528134764,1960825672,7305767602,27307800400, 102371942932,384806950624,1450038737668, 5476570993440,20727983587220,78606637060012] |