n | a(n) |
---|---|
0 | 1 |
1 | 6 |
2 | 30 |
3 | 120 |
4 | 435 |
5 | 1446 |
6 | 4536 |
7 | 13560 |
8 | 39045 |
9 | 108950 |
10 | 296178 |
11 | 787368 |
12 | 2053335 |
13 | 5265750 |
14 | 13306380 |
15 | 33188040 |
16 | 81815145 |
17 | 199585830 |
18 | 482290630 |
19 | 1155444120 |
20 | 2746489851 |
21 | 6481600326 |
22 | 15195437280 |
23 | 35407315800 |
24 | 82038719565 |
25 | 189089191926 |
26 | 433704632346 |
27 | 990244936520 |
[1,6,30,120,435,1446,4536,13560,39045,108950, 296178,787368,2053335,5265750,13306380,33188040, 81815145,199585830,482290630,1155444120, 2746489851,6481600326,15195437280,35407315800, 82038719565,189089191926,433704632346, 990244936520] |