n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 4 |
3 | 13 |
4 | 52 |
5 | 209 |
6 | 906 |
7 | 4010 |
8 | 18303 |
9 | 85064 |
10 | 402008 |
11 | 1924412 |
12 | 9314594 |
13 | 45502924 |
14 | 224068334 |
15 | 1111017056 |
16 | 5542331502 |
17 | 27796367468 |
18 | 140072333426 |
19 | 708875098462 |
20 | 3601278993411 |
21 | 18359296689521 |
22 | 93892611212526 |
23 | 481575492271765 |
24 | 2476572824391335 |
25 | 12767331527712854 |
[1,1,4,13,52,209,906,4010,18303,85064,402008, 1924412,9314594,45502924,224068334,1111017056, 5542331502,27796367468,140072333426,708875098462, 3601278993411,18359296689521,93892611212526, 481575492271765,2476572824391335, 12767331527712854] |