n | a(n) |
---|---|
0 | 1 |
1 | 9 |
2 | 45 |
3 | 165 |
4 | 495 |
5 | 1287 |
6 | 3003 |
7 | 6435 |
8 | 12870 |
9 | 24311 |
10 | 43776 |
11 | 75753 |
12 | 127110 |
13 | 209475 |
14 | 346104 |
15 | 591261 |
16 | 1081575 |
17 | 2163150 |
18 | 4686826 |
19 | 10656387 |
20 | 24582663 |
21 | 56191734 |
22 | 125640180 |
23 | 273241161 |
24 | 577147212 |
25 | 1184959314 |
26 | 2369918628 |
27 | 4631710931 |
28 | 8881943832 |
29 | 16798969548 |
30 | 31537530456 |
[1,9,45,165,495,1287,3003,6435,12870,24311,43776, 75753,127110,209475,346104,591261,1081575,2163150, 4686826,10656387,24582663,56191734,125640180, 273241161,577147212,1184959314,2369918628, 4631710931,8881943832,16798969548,31537530456] |