n | a(n) |
---|---|
0 | 1 |
1 | 3 |
2 | 12 |
3 | 51 |
4 | 222 |
5 | 978 |
6 | 4338 |
7 | 19323 |
8 | 86310 |
9 | 386250 |
10 | 1730832 |
11 | 7763550 |
12 | 34847796 |
13 | 156503064 |
14 | 703149438 |
15 | 3160160811 |
16 | 14206181382 |
17 | 63874779714 |
18 | 287242041528 |
19 | 1291872728826 |
20 | 5810776384932 |
21 | 26138647551564 |
22 | 117587214581508 |
[1,3,12,51,222,978,4338,19323,86310,386250, 1730832,7763550,34847796,156503064,703149438, 3160160811,14206181382,63874779714,287242041528, 1291872728826,5810776384932,26138647551564, 117587214581508] |