n | a(n) |
---|---|
1 | 1 |
2 | 4 |
3 | 15 |
4 | 48 |
5 | 190 |
6 | 600 |
7 | 2205 |
8 | 6720 |
9 | 29988 |
10 | 95760 |
11 | 364980 |
12 | 1108800 |
13 | 4813380 |
14 | 15135120 |
15 | 57432375 |
16 | 172972800 |
17 | 892371480 |
18 | 2916033120 |
19 | 11616348744 |
20 | 35384469120 |
21 | 162510369840 |
22 | 514937142720 |
23 | 1992665514840 |
24 | 5996736345600 |
25 | 30797112654000 |
26 | 100124080056000 |
[1,4,15,48,190,600,2205,6720,29988,95760,364980, 1108800,4813380,15135120,57432375,172972800, 892371480,2916033120,11616348744,35384469120, 162510369840,514937142720,1992665514840, 5996736345600,30797112654000,100124080056000] |