n | a(n) |
---|---|
1 | 1 |
2 | 4 |
3 | 12 |
4 | 36 |
5 | 132 |
6 | 396 |
7 | 1716 |
8 | 5148 |
9 | 25740 |
10 | 87516 |
11 | 437580 |
12 | 1662804 |
13 | 8314020 |
14 | 38244492 |
15 | 167943204 |
16 | 839716020 |
17 | 3862693692 |
18 | 17298150012 |
19 | 86490750060 |
20 | 397857450276 |
21 | 1850902051284 |
22 | 9254510256420 |
23 | 42570747179532 |
24 | 201748323589956 |
25 | 1008741617949780 |
26 | 4640211442568988 |
[1,4,12,36,132,396,1716,5148,25740,87516,437580, 1662804,8314020,38244492,167943204,839716020, 3862693692,17298150012,86490750060,397857450276, 1850902051284,9254510256420,42570747179532, 201748323589956,1008741617949780,4640211442568988] |