n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 13 |
4 | 57 |
5 | 252 |
6 | 1322 |
7 | 7361 |
8 | 45057 |
9 | 294392 |
10 | 2054394 |
11 | 15172872 |
12 | 118175823 |
13 | 966300054 |
14 | 8268640847 |
15 | 73825951226 |
16 | 686049132714 |
17 | 6620780612228 |
18 | 66224775509130 |
19 | 685372810735380 |
20 | 7327272883303533 |
[1,1,4,13,57,252,1322,7361,45057,294392,2054394, 15172872,118175823,966300054,8268640847, 73825951226,686049132714,6620780612228, 66224775509130,685372810735380,7327272883303533] |