n | a(n) |
---|---|
2 | 4 |
3 | 35 |
4 | 252 |
5 | 1716 |
6 | 11440 |
7 | 75582 |
8 | 497420 |
9 | 3268760 |
10 | 21474180 |
11 | 141120525 |
12 | 927983760 |
13 | 6107086800 |
14 | 40225345056 |
15 | 265182149218 |
16 | 1749695026860 |
17 | 11554258485616 |
18 | 76360380541900 |
19 | 505037289962205 |
20 | 3342649210440540 |
21 | 22138745874816900 |
22 | 146721427591999680 |
[4,35,252,1716,11440,75582,497420,3268760, 21474180,141120525,927983760,6107086800, 40225345056,265182149218,1749695026860, 11554258485616,76360380541900,505037289962205, 3342649210440540,22138745874816900, 146721427591999680] |