n | a(n) |
---|---|
0 | 1 |
1 | 12 |
2 | 90 |
3 | 540 |
4 | 2835 |
5 | 13608 |
6 | 61236 |
7 | 262440 |
8 | 1082565 |
9 | 4330260 |
10 | 16888014 |
11 | 64481508 |
12 | 241805655 |
13 | 892820880 |
14 | 3252418920 |
15 | 11708708112 |
16 | 41712272649 |
17 | 147219785820 |
18 | 515269250370 |
19 | 1789882659180 |
20 | 6175095174171 |
21 | 21171754882872 |
[1,12,90,540,2835,13608,61236,262440,1082565, 4330260,16888014,64481508,241805655,892820880, 3252418920,11708708112,41712272649,147219785820, 515269250370,1789882659180,6175095174171, 21171754882872] |