# SignalDesk AI Binomial Coefficient Calculator

> SignalDesk AI Binomial Coefficient Calculator is a paid API for AI agents from x402-agent.kariguetoazul.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-10-13).

Computes the binomial coefficient C(n, k) — the number of ways to choose k items from n items — and returns the result as a string.

## Facts

- Endpoint: POST https://x402-agent.kariguetoazul.workers.dev/api/math/binomial?utm_source=zero.xyz
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-13
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/signaldesk-ai-binomial-coefficient-calculator-3bec5aea
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QD6kjrHu4h2l0pWwPZuAH

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability signaldesk-ai-binomial-coefficient-calculator-3bec5aea -d '<json body>'
```

Example prompt: What is 10 choose 3? I need the exact number of combinations — use the binomial coefficient calculator with n=10 and k=3.

## When to prefer this

Choose this endpoint when you need a precise integer computation of C(n,k) for combinatorics, probability, or statistics tasks. It is ideal for agents that need a fast, reliable, server-side calculation rather than relying on local math libraries. Useful when n and k are within 0–1000 and you require an exact large-integer result returned as a string.

## Known failure modes

- k > n: mathematically undefined or returns 0 depending on implementation
- n or k outside 0–1000 range: request rejected due to schema maximum/minimum constraints
- missing required fields n or k: likely 400 Bad Request
- very large values of n close to 1000 may produce extremely large numbers that overflow typical integer representations
- payment failure via x402: request blocked if USDC payment not included or insufficient

## How this service works

Evidence-backed autonomous AI jobs and paid data tools. Queue/D1/cron run outside the chat; free quotas and bounded execution apply.

## Output

A JSON object with a single field `combinations` containing the binomial coefficient C(n, k) as a numeric string (e.g. {"combinations": "120"} for C(10,3)=120).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "k": {
   "type": "integer",
   "maximum": 1000,
   "minimum": 0,
   "description": "k."
  },
  "n": {
   "type": "integer",
   "maximum": 1000,
   "minimum": 0,
   "description": "n."
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "combinations": "120"
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/signaldesk-ai-binomial-coefficient-calculator-3bec5aea/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-agent.kariguetoazul.workers.dev](https://www.zero.xyz/host/x402-agent.kariguetoazul.workers.dev/llms.txt)