n | a(n) |
---|---|
0 | 1 |
1 | 4 |
2 | 12 |
3 | 44 |
4 | 144 |
5 | 528 |
6 | 1808 |
7 | 6676 |
8 | 23536 |
9 | 87568 |
10 | 315136 |
11 | 1180680 |
12 | 4314560 |
13 | 16263896 |
14 | 60138816 |
15 | 227899484 |
16 | 850600944 |
17 | 3238194560 |
18 | 12177384544 |
19 | 46542879384 |
20 | 176110444736 |
21 | 675431779856 |
22 | 2568878867200 |
23 | 9882068082112 |
24 | 37747540858240 |
25 | 145593279888736 |
26 | 558190182662144 |
[1,4,12,44,144,528,1808,6676,23536,87568,315136, 1180680,4314560,16263896,60138816,227899484, 850600944,3238194560,12177384544,46542879384, 176110444736,675431779856,2568878867200, 9882068082112,37747540858240,145593279888736, 558190182662144] |