Math & Numbers
Combination Calculator
Calculate combinations (C(n,r)) with support for different types: with/without repetition, binomial coefficients, and detailed combinatorial analysis.
json· JSON resultOpen tool
Quick start
Call this tool from your code in three languages.
cURL
curl -X POST 'https://api.elysiatools.com/en/api/tools/combination-calculator' \
-H 'Content-Type: application/json' \
-d '{"n":10,"r":3,"type":"without_repetition","showFormula":true,"showSteps":true,"showPascalTriangle":false}'API reference
Send a POST request with your inputs as JSON. File parameters require a separate upload first.
Endpoint
HTTP
POST https://api.elysiatools.com/en/api/tools/combination-calculatorParameters
| Name | Type | Required | Description |
|---|---|---|---|
| n | number | Yes | — |
| r | number | Yes | — |
| type | select | Yes | — |
| showFormula | checkbox | No | — |
| showSteps | checkbox | No | — |
| showPascalTriangle |
MCP integration
Add this tool to your Model Context Protocol server so AI agents can list and call it.
Server configuration
Add this block to your MCP client configuration:
mcp.json
{
"mcpServers": {
"elysiatools-combination-calculator": {
"name": "combination-calculator",
"description": "Calculate combinations (C(n,r)) with support for different types: with/without repetition, binomial coefficients, and detailed combinatorial analysis.",
"baseUrl": "https://api.elysiatools.com/mcp/sse?toolId=combination-calculator",
"command": "",
"args": [],
"env": {},
"isActive": true,
"type": "sse"
}
}
}List available tools
After connecting to the SSE endpoint, list the exposed tools:
tools/list
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}Call this tool
Invoke the tool by its id, passing arguments built from its parameters:
tools/call
{
"jsonrpc": "2.0",
"id": 2,
"method": "tools/call",
"params": {
"name": "combination-calculator",
"arguments": {
"n": 10,
"r": 3,
"type": "without_repetition",
"showFormula": true,
"showSteps": true,
"showPascalTriangle": false
}
}
}Chain multiple tools in one session with a comma-separated toolId list, e.g. /mcp/sse?toolId=png-to-webp,jpg-to-webp,gif-to-webp (max 20).
Questions or issues? Contact [email protected]