n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 25 |
4 | 211 |
5 | 2238 |
6 | 28560 |
7 | 425808 |
8 | 7261200 |
9 | 139367278 |
10 | 2973006344 |
11 | 69775267186 |
12 | 1786673529746 |
13 | 49565881948204 |
14 | 1480900541242572 |
15 | 47407364553205448 |
16 | 1618838460981098680 |
17 | 58734896900587841824 |
18 | 2256402484187691207152 |
19 | 91499934912942249975504 |
20 | 3905739517580787866827872 |
[1,1,4,25,211,2238,28560,425808,7261200,139367278, 2973006344,69775267186,1786673529746, 49565881948204,1480900541242572,47407364553205448, 1618838460981098680,58734896900587841824, 2256402484187691207152,91499934912942249975504, 3905739517580787866827872] |