n | a(n) |
---|---|
1 | 0 |
2 | 0 |
3 | 1 |
4 | 4 |
5 | 20 |
6 | 86 |
7 | 409 |
8 | 1988 |
9 | 10404 |
10 | 57488 |
11 | 338180 |
12 | 2103378 |
13 | 13814202 |
14 | 95423766 |
15 | 691415451 |
16 | 5239857008 |
17 | 41431883216 |
18 | 341036489096 |
19 | 2916365967707 |
20 | 25862060748614 |
21 | 237434856965694 |
22 | 2253357681164288 |
23 | 22076002386446896 |
24 | 222979432604192844 |
25 | 2319295160051570620 |
[0,0,1,4,20,86,409,1988,10404,57488,338180, 2103378,13814202,95423766,691415451,5239857008, 41431883216,341036489096,2916365967707, 25862060748614,237434856965694,2253357681164288, 22076002386446896,222979432604192844, 2319295160051570620] |