n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 20 |
4 | 130 |
5 | 1052 |
6 | 10214 |
7 | 115684 |
8 | 1497458 |
9 | 21806372 |
10 | 352834942 |
11 | 6279885284 |
12 | 121932835754 |
13 | 2564788969108 |
14 | 58098821674742 |
15 | 1410088008633812 |
16 | 36505125340079074 |
17 | 1004131069129741124 |
18 | 29244927598399536878 |
19 | 899066450011962665092 |
20 | 29094401487631077315482 |
21 | 988590340245276942963764 |
[1,1,4,20,130,1052,10214,115684,1497458,21806372, 352834942,6279885284,121932835754,2564788969108, 58098821674742,1410088008633812,36505125340079074, 1004131069129741124,29244927598399536878, 899066450011962665092,29094401487631077315482, 988590340245276942963764] |