Here's the list beautified for markdown:

Most Popular Problems for Facebook (last 6 months)

1. Minimum Remove to Make Valid Parentheses (45 times)
2. Valid Palindrome II (38 times)
3. Buildings With an Ocean View (34 times)
4. Binary Tree Vertical Order Traversal (33 times)
5. Kth Largest Element in an Array (31 times)
6. Random Pick with Weight (28 times)
7. Lowest Common Ancestor of a Binary Tree (26 times)
8. Simplify Path (25 times)
9. Dot Product of Two Sparse Vectors (24 times)
10. Merge Intervals (24 times)
11. Lowest Common Ancestor of a Binary Tree III (21 times)
12. Two Sum (19 times)
13. Valid Word Abbreviation (19 times)
14. Nested List Weight Sum (18 times)
15. Basic Calculator II (18 times)
16. Valid Palindrome (18 times)
17. Find Peak Element (17 times)
18. Binary Tree Right Side View (17 times)
19. Pow(x, n) (17 times)
20. Shortest Path in Binary Matrix (16 times)
21. K Closest Points to Origin (15 times)
22. Subarray Sum Equals K (15 times)
23. Minimum Add to Make Parentheses Valid (14 times)
24. Range Sum of BST (14 times)
25. Top K Frequent Elements (13 times)
26. Diameter of Binary Tree (12 times)
27. Find First and Last Position of Element in Sorted Array (12 times)
28. Merge Sorted Array (12 times)
29. Valid Parentheses (11 times)
30. Group Shifted Strings (11 times)
31. Vertical Order Traversal of a Binary Tree (11 times)
32. Roman to Integer (11 times)
33. Move Zeroes (10 times)
34. Continuous Subarray Sum (10 times)
35. Partition Equal Subset Sum (10 times)
36. Valid Number (10 times)
37. Number of Islands (9 times)
38. Copy List with Random Pointer (9 times)
39. 3Sum (9 times)
40. Next Permutation (9 times)
41. Moving Average from Data Stream (9 times)
42. Best Time to Buy and Sell Stock (8 times)
43. Longest Substring Without Repeating Characters (8 times)
44. Custom Sort String (8 times)
45. LRU Cache (8 times)
46. Subsets (8 times)
47. Remove Nth Node From End of List (8 times)
48. Remove Invalid Parentheses (8 times)
49. Sum Root to Leaf Numbers (7 times)
50. Insert into a Sorted Circular Linked List (7 times)
51. Word Break (7 times)
52. Maximum Subarray (7 times)
53. Merge k Sorted Lists (7 times)
54. Binary Search Tree Iterator (7 times)
55. Add Two Numbers (7 times)
56. Max Consecutive Ones III (7 times)
57. Find Pivot Index (6 times)
58. Clone Graph (6 times)
59. Diagonal Traverse (6 times)
60. Word Search (6 times)
61. Group Anagrams (6 times)
62. Merge Two Sorted Lists (6 times)
63. Word Ladder
64. Jump Game
65. Jump Game II
66. Interval List Intersections