n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 21 |
3 | 126 |
4 | 797 |
5 | 5190 |
6 | 34439 |
7 | 231556 |
8 | 1572135 |
9 | 10754148 |
10 | 74001735 |
11 | 511686726 |
12 | 3552251429 |
13 | 24743806370 |
14 | 172853699427 |
15 | 1210514603212 |
16 | 8495774193707 |
17 | 59739915525288 |
18 | 420785972800187 |
19 | 2968344133842182 |
20 | 20967995689677183 |
[1,4,21,126,797,5190,34439,231556,1572135, 10754148,74001735,511686726,3552251429, 24743806370,172853699427,1210514603212, 8495774193707,59739915525288,420785972800187, 2968344133842182,20967995689677183] |