n | a(n) |
---|---|
1 | 0 |
2 | 4 |
3 | 132 |
4 | 256 |
5 | 5260 |
6 | 37636 |
7 | 321696 |
8 | 2951524 |
9 | 26486820 |
10 | 229461904 |
11 | 2051332140 |
12 | 18106931844 |
13 | 160285145184 |
14 | 1419610292676 |
15 | 12571883432500 |
16 | 111281907352576 |
17 | 985420995488860 |
18 | 8724655803209956 |
19 | 77248992679400736 |
20 | 683971842578913604 |
[0,4,132,256,5260,37636,321696,2951524,26486820, 229461904,2051332140,18106931844,160285145184, 1419610292676,12571883432500,111281907352576, 985420995488860,8724655803209956, 77248992679400736,683971842578913604] |