n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 7 |
4 | 30 |
5 | 75 |
6 | 323 |
7 | 927 |
8 | 4084 |
9 | 12757 |
10 | 57357 |
11 | 190323 |
12 | 863932 |
13 | 2990215 |
14 | 13742390 |
15 | 49151253 |
16 | 227407578 |
17 | 834395673 |
18 | 3888507313 |
19 | 14572098227 |
20 | 68261017116 |
21 | 260231521603 |
22 | 1224649653002 |
23 | 4738562044311 |
24 | 22388087279914 |
25 | 87710572097589 |
26 | 415756729437735 |
27 | 1646822285537643 |
28 | 7829736984834466 |
[1,1,4,7,30,75,323,927,4084,12757,57357,190323, 863932,2990215,13742390,49151253,227407578, 834395673,3888507313,14572098227,68261017116, 260231521603,1224649653002,4738562044311, 22388087279914,87710572097589,415756729437735, 1646822285537643,7829736984834466] |