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Oeis

Official registry Other

OEIS (On-Line Encyclopedia of Integer Sequences) MCP.

Source code Website Documentation

Install

Add this to your client's MCP configuration (Claude Desktop: claude_desktop_config.json; Cursor: .cursor/mcp.json; VS Code and others use the same "mcpServers" shape).

Remote (streamable-http)
Claude Code 
claude mcp add --transport http oeis 'https://gateway.pipeworx.io/oeis/mcp'
JSON configuration (Claude Desktop, Cursor, VS Code) 
{
    "mcpServers": {
        "oeis": {
            "type": "http",
            "url": "https://gateway.pipeworx.io/oeis/mcp"
        }
    }
}

Documentation

From the project's README on GitHub, refreshed weekly. Links open on GitHub.

Contents
  1. mcp-oeis
  2. Tools
  3. Quick Start
  4. No MCP client? Call it over HTTP
  5. Standalone (no gateway account)
  6. Using with ask_pipeworx
  7. More
  8. License

mcp-oeis

OEIS (On-Line Encyclopedia of Integer Sequences) MCP.

Part of Pipeworx — an MCP gateway connecting AI agents to 1683+ live data sources.

Tools

ToolDescription
search_sequenceSearch the OEIS (On-Line Encyclopedia of Integer Sequences), the authoritative database of integer sequences. Identify a sequence from its first terms by passing a comma-separated list of integers (e.g. "1,1,2,3,5,8" finds the Fibonacci numbers), look up a specific sequence by A-number (e.g. "A000045"), or search free-text keywords (e.g. "prime gaps"). Returns up to 10 matching sequences per page with their A-number, name, terms, keywords, author, and offset. Use the start argument to paginate (10 results at a time).
get_sequenceFetch a single OEIS integer sequence by its A-number (e.g. "A000045" for the Fibonacci numbers, "A000040" for the primes). Accepts the A-number with or without the "A" prefix and zero-padding ("A000045", "45", and "000045" are all valid). Returns the full record: name, terms (data), comments, formulas, keywords, offset, author, and reference count. Use this to get the formula or mathematical description of a known sequence.

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "oeis": {
      "url": "https://gateway.pipeworx.io/oeis/mcp"
    }
  }
}
What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/oeis/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — ask_pipeworx, discover_tools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a scoped connection answer a question this pack does not cover — via ask_pipeworx, which routes across the whole catalog — without you adding a second MCP server. There is currently no way to mount a pack endpoint without them; if the extra schemas cost you more context than the routing is worth, connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:

{
  "mcpServers": {
    "pipeworx": {
      "url": "https://gateway.pipeworx.io/mcp"
    }
  }
}

Both URLs reach the same gateway and the same 1683+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

curl -X POST https://gateway.pipeworx.io/v1/tools/search_sequence \
  -H 'Content-Type: application/json' \
  -d '{"query":"1,1,2,3,5,8"}'

No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/search_sequence. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Standalone (no gateway account)

This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:

{
  "mcpServers": {
    "oeis": {
      "command": "npx",
      "args": ["-y", "@pipeworx/mcp-oeis"]
    }
  }
}

Or run it directly to confirm it starts:

npx -y @pipeworx/mcp-oeis

It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call for only this pack's tools — none of the shared meta-tools the gateway connection above adds. Same source, same tools, no ask_pipeworx routing.

Using with ask_pipeworx

Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:

ask_pipeworx({ question: "your question about Oeis data" })

The gateway picks the right tool and fills the arguments automatically.

More

License

MIT

Frequently asked questions

What is Oeis?

OEIS (On-Line Encyclopedia of Integer Sequences) MCP.

How do I install Oeis?

It runs as a remote server. In Claude Code: claude mcp add --transport http oeis 'https://gateway.pipeworx.io/oeis/mcp'. For other clients, paste the JSON configuration from this page into their MCP settings.

Does Oeis need an API key?

Its registry entry lists no required key or secret. Some features may still need an account with the service it connects to.

Is Oeis open source?

Yes. Its code is on GitHub under the MIT license.

Who maintains Oeis?

It is published by pipeworx-io. AI.tn lists it but does not maintain or endorse it.

From the official MCP Registry. Listing is not an endorsement: review a server's code and permissions before giving it access to your data.