1 1
2 3
3 6
4 11
5 17
6 28
7 40
8 63
9 90
10 143
11 197
12 304
13 436
14 699
15 963
16 1490
17 2147
18 3460
19 4816
20 7527
21 10914
22 17687
23 24461
24 38008
25 54940
26 88803
27 124011
28 194426
29 282443
30 458476
31 634510
32 986577
33 1426659
34 2306822
35 3222182
36 5052901
37 7341298
38 11918091
39 16501395
40 25668002
41 37126259
42 60042772
43 83875936
44 131542263
45 191125170
46 310290983
47 429456797
48 667788424
49 965702956
50 1561532019
51 2181194235
52 3420518666