n | a(n) |
---|---|
1 | 4 |
2 | 20 |
3 | 80 |
4 | 264 |
5 | 809 |
6 | 2506 |
7 | 8432 |
8 | 30362 |
9 | 109520 |
10 | 391836 |
11 | 1408127 |
12 | 5002188 |
13 | 17308136 |
14 | 59463783 |
15 | 210199210 |
16 | 774578726 |
17 | 2918410859 |
18 | 10951007498 |
19 | 40430881133 |
20 | 146973680685 |
21 | 527988483182 |
22 | 1880363101497 |
23 | 6679919969564 |
24 | 23928818399537 |
[4,20,80,264,809,2506,8432,30362,109520,391836, 1408127,5002188,17308136,59463783,210199210, 774578726,2918410859,10951007498,40430881133, 146973680685,527988483182,1880363101497, 6679919969564,23928818399537] |