n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 27 |
3 | 212 |
4 | 1785 |
5 | 15630 |
6 | 140287 |
7 | 1280592 |
8 | 11833389 |
9 | 110360150 |
10 | 1036670272 |
11 | 9794291556 |
12 | 92972640761 |
13 | 886023463122 |
14 | 8471878678545 |
15 | 81236546627920 |
16 | 780898417097733 |
17 | 7522708492892214 |
18 | 72607180401922894 |
19 | 701969331508141900 |
20 | 6796919869909393140 |
[1,4,27,212,1785,15630,140287,1280592,11833389, 110360150,1036670272,9794291556,92972640761, 886023463122,8471878678545,81236546627920, 780898417097733,7522708492892214, 72607180401922894,701969331508141900, 6796919869909393140] |