n | a(n) |
---|---|
1 | 1 |
2 | 1 |
3 | 4 |
4 | 25 |
5 | 221 |
6 | 2505 |
7 | 34707 |
8 | 568177 |
9 | 10731571 |
10 | 229706718 |
11 | 5495040882 |
12 | 145285035974 |
13 | 4206973447847 |
14 | 132410823640004 |
15 | 4500857134998016 |
16 | 164322352411837139 |
17 | 6412953180173688644 |
18 | 266421162165751276297 |
[1,1,4,25,221,2505,34707,568177,10731571, 229706718,5495040882,145285035974,4206973447847, 132410823640004,4500857134998016, 164322352411837139,6412953180173688644, 266421162165751276297] |