1. **Problem Statement:** You have a sequence of private keys and their corresponding Bitcoin addresses. The keys increment in some pattern, starting from a known initial key and address. You want to find the last 4 private keys after the key \(0000000000000000000000000000000000000000000000349b84b6431a6c4ef1\) and before \(0000000000000000000000000000000000000000000004c5ce114686a1336e07\). 2. **Understanding the Problem:** Private keys are large hexadecimal numbers. The keys you provided seem to be increasing in value. The goal is to find the 4 keys that come immediately after the key ending with \(349b84b6431a6c4ef1\) and before the key ending with \(4c5ce114686a1336e07\). 3. **Formula and Approach:** Since private keys are hexadecimal numbers, the increment between keys is numeric in base 16. To find the next keys, convert the given key to a decimal number, add 1 for each subsequent key, then convert back to hexadecimal. 4. **Step-by-step:** - Convert the key \(0000000000000000000000000000000000000000000000349b84b6431a6c4ef1\) to decimal. - Add 1 to get the next key, convert back to hex. Repeat to get 4 keys. - Ensure the keys are 64 hex characters long (pad with leading zeros if needed). 5. **Example:** Let \(K = 0x349b84b6431a6c4ef1\) (shortened for clarity). The next keys are \(K+1\), \(K+2\), \(K+3\), \(K+4\). 6. **Important:** The full private key is 64 hex characters, so pad the result with leading zeros to maintain length. 7. **Summary:** Use a script or tool to convert the hex key to decimal, increment, then convert back to hex with padding. This will give you the next 4 private keys in sequence. If you want, I can help you generate these keys explicitly.