n | a(n) |
---|---|
0 | 1 |
1 | 0 |
2 | 1 |
3 | 2 |
4 | 4 |
5 | 10 |
6 | 30 |
7 | 98 |
8 | 338 |
9 | 1240 |
10 | 4877 |
11 | 20496 |
12 | 91213 |
13 | 426678 |
14 | 2090081 |
15 | 10702438 |
16 | 57193760 |
17 | 318283388 |
18 | 1840036058 |
19 | 11026424446 |
20 | 68370955450 |
21 | 438039068726 |
22 | 2896018310881 |
23 | 19733372875632 |
24 | 138418266287689 |
25 | 998363508783924 |
26 | 7396739279819185 |
27 | 56239695790595786 |
[1,0,1,2,4,10,30,98,338,1240,4877,20496,91213, 426678,2090081,10702438,57193760,318283388, 1840036058,11026424446,68370955450,438039068726, 2896018310881,19733372875632,138418266287689, 998363508783924,7396739279819185, 56239695790595786] |