n | a(n) |
---|---|
1 | 0 |
2 | 1 |
3 | 7 |
4 | 46 |
5 | 326 |
6 | 2556 |
7 | 22212 |
8 | 212976 |
9 | 2239344 |
10 | 25659360 |
11 | 318540960 |
12 | 4261576320 |
13 | 61148511360 |
14 | 937030429440 |
15 | 15275952518400 |
16 | 264030355814400 |
17 | 4823280687052800 |
18 | 92865738644582400 |
19 | 1879691760950169600 |
20 | 39905092126771200000 |
21 | 886664974825728000000 |
[0,1,7,46,326,2556,22212,212976,2239344,25659360, 318540960,4261576320,61148511360,937030429440, 15275952518400,264030355814400,4823280687052800, 92865738644582400,1879691760950169600, 39905092126771200000,886664974825728000000] |