n   a(n) example
-------------------------
0      1 1
1      1 10
2      2 100
3      3 1010
4      4 10010
5      6 100110
6      9 1011001
7     13 10110010
8     20 101100101
9     29 1001101001
10    42 10010110010
11    65 101001101001
12    95 1011001011001
13   136 10010110010110
14   212 101100101100101
15   308 1001101001101001
16   444 10010110010110010
17   687 101001101001101001
18  1005 1011001011001011001
19  1439 10010110010110010110
20  2242 101100101100101100101
21  3257 1001101001101001101001
22  4696 10010110010110010110010
23  7266 101001101001101001101001
24 10629 1011001011001011001011001
25 15219 10010110010110010110010110