n | a(n) |
---|---|
0 | 0 |
1 | 2 |
2 | 4 |
3 | 14 |
4 | 64 |
5 | 362 |
6 | 2428 |
7 | 18806 |
8 | 165016 |
9 | 1616786 |
10 | 17487988 |
11 | 206918942 |
12 | 2657907184 |
13 | 36828901754 |
14 | 547499510764 |
15 | 8691268384262 |
16 | 146725287298888 |
17 | 2624698909845026 |
18 | 49592184973992676 |
19 | 986871395973226286 |
20 | 20630087248996393888 |
21 | 451982388752415571082 |
[0,2,4,14,64,362,2428,18806,165016,1616786, 17487988,206918942,2657907184,36828901754, 547499510764,8691268384262,146725287298888, 2624698909845026,49592184973992676, 986871395973226286,20630087248996393888, 451982388752415571082] |