3583. Count Special Triplets

You are given an integer array nums. A special triplet is defined as a triplet of indices (i, j, k) such that: - 0 <= i < j < k < n, where n = nums.length - nums[i] == nums[j] * 2 - nums[k] == nums[j] * 2 Return the total number of special triplets in the array. Since the answer may be large, return it modulo 109 + 7. Example 1: Input: nums = [6,3,6] Output: 1 Explanation: The only sp