n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | 4 |
3 | 30 |
4 | 320 |
5 | 4400 |
6 | 73872 |
7 | 1462552 |
8 | 33325056 |
9 | 858283776 |
10 | 24641000000 |
11 | 779935205984 |
12 | 26972930949120 |
13 | 1011642325897216 |
14 | 40890444454377728 |
15 | 1771640957790000000 |
16 | 81896889467638120448 |
17 | 4022826671022707900416 |
18 | 209224123984489179202560 |
[0,1,4,30,320,4400,73872,1462552,33325056, 858283776,24641000000,779935205984,26972930949120, 1011642325897216,40890444454377728, 1771640957790000000,81896889467638120448, 4022826671022707900416,209224123984489179202560] |