n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 36 |
3 | 156 |
4 | 740 |
5 | 3040 |
6 | 12852 |
7 | 52648 |
8 | 214820 |
9 | 865744 |
10 | 3487180 |
11 | 13994100 |
12 | 56047356 |
13 | 224295004 |
14 | 897465820 |
15 | 3590094664 |
[1,4,36,156,740,3040,12852,52648,214820,865744, 3487180,13994100,56047356,224295004,897465820, 3590094664] |