n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 3 |
3 | 9 |
4 | 28 |
5 | 90 |
6 | 297 |
7 | 1001 |
8 | 3432 |
9 | 11934 |
10 | 41990 |
11 | 149226 |
12 | 534888 |
13 | 1931540 |
14 | 7020405 |
15 | 25662825 |
16 | 94287120 |
17 | 347993910 |
18 | 1289624490 |
19 | 4796857230 |
20 | 17902146600 |
21 | 67016296620 |
22 | 251577050010 |
23 | 946844533674 |
24 | 3572042254128 |
25 | 13505406670700 |
[1,1,3,9,28,90,297,1001,3432,11934,41990,149226, 534888,1931540,7020405,25662825,94287120, 347993910,1289624490,4796857230,17902146600, 67016296620,251577050010,946844533674, 3572042254128,13505406670700] |