n | a(n) |
---|---|
0 | 1 |
1 | 21 |
2 | 420 |
3 | 8400 |
4 | 168000 |
5 | 3360000 |
6 | 67200000 |
7 | 1344000000 |
8 | 26880000000 |
9 | 537600000000 |
10 | 10752000000000 |
11 | 215040000000000 |
12 | 4300800000000000 |
13 | 86016000000000000 |
14 | 1720320000000000000 |
15 | 34406400000000000000 |
16 | 688128000000000000000 |
17 | 13762560000000000000000 |
18 | 275251200000000000000000 |
[1,21,420,8400,168000,3360000,67200000,1344000000, 26880000000,537600000000,10752000000000, 215040000000000,4300800000000000, 86016000000000000,1720320000000000000, 34406400000000000000,688128000000000000000, 13762560000000000000000,275251200000000000000000] |