# Hailstone Sequence > Compute the complete Hailstone sequence for a given starting number by repeatedly calling the next_number tool until the value 1 is reached. Use when this capability is needed. - Skill: `tomevault-io/hailstone-sequence` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/hailstone-sequence` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/hailstone-sequence/raw - Safety review: pending (external: skill-scanner PASS, skillspector PASS) - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/hailstone-sequence --- # Hailstone Sequence Compute the full Hailstone (Collatz) sequence from a starting number down to 1 using the `next_number` tool. ## Arguments The user must provide a **starting number** (a positive integer greater than 1). If no starting number is given, ask the user before proceeding. ## Steps ### 1. Initialize Set the current number `x` to the starting number provided by the user. Begin tracking the sequence as a list: `[x]`. ### 2. Call the tool Call `next_number` with the current value of `x`. ``` next_number(x=) ``` **STOP and WAIT** for the tool result before continuing. ### 3. Record the result Append the returned value to the sequence list. Set `x` to the returned value. ### 4. Check termination - If `x == 1`, proceed to Step 5. - Otherwise, go back to Step 2. **Important rules:** - NEVER fabricate or simulate tool call results. - NEVER make multiple tool calls in a single response. - ALWAYS wait for the actual tool response before deciding next steps. ### 5. Report the result Print the complete sequence from start to finish, for example: ``` 6 → 3 → 10 → 5 → 16 → 8 → 4 → 2 → 1 ``` Also report: - **Starting number** - **Total steps taken** (number of tool calls made) - **Maximum value reached** in the sequence --- > Source: [nerdai/llm-agents-from-scratch](https://github.com/nerdai/llm-agents-from-scratch) — distributed by [TomeVault](https://tomevault.io).