n | a(n) |
---|---|
0 | 0 |
1 | 1 |
2 | -1 |
3 | 2 |
4 | -1 |
5 | 4 |
6 | 2 |
7 | 13 |
8 | 23 |
9 | 68 |
10 | 164 |
11 | 439 |
12 | 1146 |
13 | 3067 |
14 | 8231 |
15 | 22306 |
16 | 60791 |
17 | 166684 |
18 | 459308 |
19 | 1271479 |
20 | 3534116 |
21 | 9859573 |
22 | 27598757 |
23 | 77490472 |
24 | 218183522 |
25 | 615902899 |
26 | 1742738477 |
27 | 4942022648 |
28 | 14043034703 |
29 | 39979680748 |
30 | 114020882010 |
31 | 325721340061 |
[0,1,-1,2,-1,4,2,13,23,68,164,439,1146,3067,8231, 22306,60791,166684,459308,1271479,3534116,9859573, 27598757,77490472,218183522,615902899,1742738477, 4942022648,14043034703,39979680748,114020882010, 325721340061] |