n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 15 |
4 | 47 |
5 | 160 |
6 | 517 |
7 | 1721 |
8 | 5668 |
9 | 18687 |
10 | 61687 |
11 | 203448 |
12 | 671253 |
13 | 2214377 |
14 | 7305308 |
15 | 24100319 |
16 | 79506903 |
17 | 262294336 |
18 | 865310405 |
19 | 2854666385 |
20 | 9417565852 |
21 | 31068622271 |
22 | 102495625503 |
23 | 338133855032 |
24 | 1115506197957 |
25 | 3680063534409 |
26 | 12140557957708 |
27 | 40051794232519 |
28 | 132131177728807 |
[1,1,4,15,47,160,517,1721,5668,18687,61687,203448, 671253,2214377,7305308,24100319,79506903, 262294336,865310405,2854666385,9417565852, 31068622271,102495625503,338133855032, 1115506197957,3680063534409,12140557957708, 40051794232519,132131177728807] |