n | a(n) |
---|---|
1 | 1 |
2 | 1 |
3 | 2 |
4 | 6 |
5 | 20 |
6 | 90 |
7 | 468 |
8 | 2910 |
9 | 20644 |
10 | 165874 |
11 | 1484344 |
12 | 14653890 |
13 | 158136988 |
14 | 1852077284 |
15 | 23394406084 |
16 | 317018563806 |
17 | 4587391330992 |
18 | 70598570456104 |
19 | 1151382852200680 |
20 | 19835976878704628 |
21 | 359963038816096924 |
22 | 6863033015330999110 |
23 | 137156667020252478684 |
24 | 2867083618970831936826 |
[1,1,2,6,20,90,468,2910,20644,165874,1484344, 14653890,158136988,1852077284,23394406084, 317018563806,4587391330992,70598570456104, 1151382852200680,19835976878704628, 359963038816096924,6863033015330999110, 137156667020252478684,2867083618970831936826] |