n | a(n) |
---|---|
0 | 1 |
1 | 1 |
2 | 1 |
3 | 4 |
4 | 9 |
5 | 26 |
6 | 91 |
7 | 281 |
8 | 1105 |
9 | 4105 |
10 | 16576 |
11 | 70643 |
12 | 301405 |
13 | 1382928 |
14 | 6363876 |
15 | 30605836 |
16 | 150820769 |
17 | 758835104 |
18 | 3941917840 |
19 | 20787546715 |
20 | 112615930451 |
21 | 620969188400 |
22 | 3492709446326 |
23 | 20034747631656 |
24 | 116780977502105 |
25 | 693539635192626 |
26 | 4181549476945504 |
27 | 25627647913369903 |
[1,1,1,4,9,26,91,281,1105,4105,16576,70643,301405, 1382928,6363876,30605836,150820769,758835104, 3941917840,20787546715,112615930451,620969188400, 3492709446326,20034747631656,116780977502105, 693539635192626,4181549476945504, 25627647913369903] |