n | a(n) |
---|---|
0 | 0 |
1 | 4 |
2 | 12 |
3 | 44 |
4 | 172 |
5 | 2220 |
6 | 10412 |
7 | 141484 |
8 | 665772 |
9 | 9054380 |
10 | 545925292 |
11 | 2693408940 |
12 | 140132362412 |
13 | 2339155617964 |
14 | 11135248640172 |
15 | 151872736995500 |
16 | 9159071991736492 |
17 | 585619824295159980 |
18 | 2891462833508853932 |
19 | 150465415423185266860 |
20 | 2511648656858007873708 |
[0,4,12,44,172,2220,10412,141484,665772,9054380, 545925292,2693408940,140132362412,2339155617964, 11135248640172,151872736995500,9159071991736492, 585619824295159980,2891462833508853932, 150465415423185266860,2511648656858007873708] |