48
Arbor (48) = 70
48 = 2*2*2*2*3
The 70 possible trees:
1. (2,(2,(2,(2,3))))
2. (2,(2,(2,(3,2))))
3. (2,(2,(3,(2,2))))
4. (2,(2,((2,2),3)))
5. (2,(2,((2,3),2)))
6. (2,(2,((3,2),2)))
7. (2,(3,(2,(2,2))))
8. (2,(3,((2,2),2)))
9. (2,((2,2),(2,3)))
10. (2,((2,2),(3,2)))
11. (2,((2,3),(2,2)))
12. (2,((3,2),(2,2)))
13. (2,((2,(2,2)),3))
14. (2,(((2,2),2),3))
15. (2,((2,(2,3)),2))
16. (2,((2,(3,2)),2))
17. (2,((3,(2,2)),2))
18. (2,(((2,2),3),2))
19. (2,(((2,3),2),2))
20. (2,(((3,2),2),2))
21. (3,(2,(2,(2,2))))
22. (3,(2,((2,2),2)))
23. (3,((2,2),(2,2)))
24. (3,((2,(2,2)),2))
25. (3,(((2,2),2),2))
26. ((2,2),(2,(2,3)))
27. ((2,2),(2,(3,2)))
28. ((2,2),(3,(2,2)))
29. ((2,2),((2,2),3))
30. ((2,2),((2,3),2))
31. ((2,2),((3,2),2))
32. ((2,3),(2,(2,2)))
33. ((2,3),((2,2),2))
34. ((3,2),(2,(2,2)))
35. ((3,2),((2,2),2))
36. ((2,(2,2)),(2,3))
37. ((2,(2,2)),(3,2))
38. (((2,2),2),(2,3))
39. (((2,2),2),(3,2))
40. ((2,(2,3)),(2,2))
41. ((2,(3,2)),(2,2))
42. ((3,(2,2)),(2,2))
43. (((2,2),3),(2,2))
44. (((2,3),2),(2,2))
45. (((3,2),2),(2,2))
46. ((2,(2,(2,2))),3)
47. ((2,((2,2),2)),3)
48. (((2,2),(2,2)),3)
49. (((2,(2,2)),2),3)
50. ((((2,2),2),2),3)
51. ((2,(2,(2,3))),2)
52. ((2,(2,(3,2))),2)
53. ((2,(3,(2,2))),2)
54. ((2,((2,2),3)),2)
55. ((2,((2,3),2)),2)
56. ((2,((3,2),2)),2)
57. ((3,(2,(2,2))),2)
58. ((3,((2,2),2)),2)
59. (((2,2),(2,3)),2)
60. (((2,2),(3,2)),2)
61. (((2,3),(2,2)),2)
62. (((3,2),(2,2)),2)
63. (((2,(2,2)),3),2)
64. ((((2,2),2),3),2)
65. (((2,(2,3)),2),2)
66. (((2,(3,2)),2),2)
67. (((3,(2,2)),2),2)
68. ((((2,2),3),2),2)
69. ((((2,3),2),2),2)
70. ((((3,2),2),2),2)