n | a(n) |
---|---|
0 | 1 |
1 | 15 |
2 | 135 |
3 | 920 |
4 | 5220 |
5 | 25893 |
6 | 115700 |
7 | 475065 |
8 | 1817910 |
9 | 6551390 |
10 | 22414314 |
11 | 73265580 |
12 | 229972855 |
13 | 696109950 |
14 | 2039031360 |
15 | 5796944357 |
16 | 16036186005 |
17 | 43259046975 |
18 | 114012183695 |
19 | 294067720380 |
20 | 743368453326 |
21 | 1844121021245 |
22 | 4494803760045 |
[1,15,135,920,5220,25893,115700,475065,1817910, 6551390,22414314,73265580,229972855,696109950, 2039031360,5796944357,16036186005,43259046975, 114012183695,294067720380,743368453326, 1844121021245,4494803760045] |