n | a(n) |
---|---|
1 | 3 |
2 | 20 |
3 | 120 |
4 | 723 |
5 | 4340 |
6 | 26040 |
7 | 156243 |
8 | 937460 |
9 | 5624760 |
10 | 33748563 |
11 | 202491380 |
12 | 1214948280 |
13 | 7289689683 |
14 | 43738138100 |
15 | 262428828600 |
16 | 1574572971603 |
17 | 9447437829620 |
18 | 56684626977720 |
19 | 340107761866323 |
20 | 2040646571197940 |
[3,20,120,723,4340,26040,156243,937460,5624760, 33748563,202491380,1214948280,7289689683, 43738138100,262428828600,1574572971603, 9447437829620,56684626977720,340107761866323, 2040646571197940] |