n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 20 |
4 | 126 |
5 | 962 |
6 | 8646 |
7 | 89546 |
8 | 1051350 |
9 | 13811642 |
10 | 200866326 |
11 | 3205348346 |
12 | 55704133590 |
13 | 1047489675962 |
14 | 21195507649686 |
15 | 459258707587706 |
16 | 10610386574074710 |
17 | 260385846630175802 |
18 | 6764666952807962646 |
[1,1,4,20,126,962,8646,89546,1051350,13811642, 200866326,3205348346,55704133590,1047489675962, 21195507649686,459258707587706,10610386574074710, 260385846630175802,6764666952807962646] |