oeis-mcp-server

io.github.cyanheads/oeis-mcp-serverVersion 0.2.0

Identify integer sequences by terms, search the OEIS, read formulas, programs, b-files, cross-refs.

Status

Responds545 msNov 14, 2026, 14:48 UTCAnswered our handshake without sign-in.

Registry data may be out of date

We could not refresh it, so this page shows the last copy.

Last checked: Nov 14, 2026, 14:48 UTC
Latency: 545 ms
Remotes responding: 1 of 1
Sign-in: No sign-in
Hosting: Hosted outside the EU (detected)
Registry data as of: Nov 14, 2026, 22:14 UTC

Data from the official MCP Registry, checked by run.zero. How we check

Connect

Streamable HTTP

https://oeis.caseyjhand.com/mcpResponds545 msNov 14, 2026, 14:48 UTC

No sign-in

Claude Code

claude mcp add --transport http oeis-mcp-server https://oeis.caseyjhand.com/mcp

Claude Desktop and claude.ai

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Settings > Connectors > Add custom connector
Name: oeis-mcp-server
Remote MCP server URL: https://oeis.caseyjhand.com/mcp

Cursor

{
  "mcpServers": {
    "oeis-mcp-server": {
      "url": "https://oeis.caseyjhand.com/mcp"
    }
  }
}

VS Code

code --add-mcp '{"name":"oeis-mcp-server","type":"http","url":"https://oeis.caseyjhand.com/mcp"}'

Streamable HTTP

npm: @cyanheads/oeis-mcp-server 0.2.0

Package only

npm (npx)

claude mcp add oeis-mcp-server -- npx -y @cyanheads/oeis-mcp-server@0.2.0

Streamable HTTP

npm: @cyanheads/oeis-mcp-server 0.2.0

Package only

npm (npx)

claude mcp add oeis-mcp-server -- npx -y @cyanheads/oeis-mcp-server@0.2.0

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Tools

6 tools

Tools of oeis-mcp-server
	Description		Read-only	Idempotent	Open world
`oeis_get_cross_refs`List sequences related to an OEIS entry. direction outgoing returns the A-numbers named in the entry's cross-reference (Cf.) lines, with any parenthetical note beside each; direction incoming returns entries that mention this A-number anywhere. Each row carries the related sequence's name and first terms. 10 rows per page.	List sequences related to an OEIS entry. direction outgoing returns the A-numbers named in the entry's cross-reference (Cf.) lines, with any parenthetical note beside each; direction incoming returns entries that mention this A-number anywhere. Each row carries the related sequence's name and first terms. 10 rows per page.	Not declared	Yes	Yes	Yes
`oeis_get_sequence`Fetch one OEIS entry by A-number. Returns the name, data-line terms, offset, keywords, author, dates, and the sections: comments, formulas (recurrences and generating functions), examples, programs (Maple, Mathematica, PARI, Python, …), references, links, cross-references, and extensions. When the sections together exceed 24,000 characters of serialized JSON, the core fields come back with a section outline instead; call again with sections to pick what to read. A selection past 100,000 bytes comes back in parts cut between items: pass nextFromItem as fromItem, with the same sections, for the next part.	Fetch one OEIS entry by A-number. Returns the name, data-line terms, offset, keywords, author, dates, and the sections: comments, formulas (recurrences and generating functions), examples, programs (Maple, Mathematica, PARI, Python, …), references, links, cross-references, and extensions. When the sections together exceed 24,000 characters of serialized JSON, the core fields come back with a section outline instead; call again with sections to pick what to read. A selection past 100,000 bytes comes back in parts cut between items: pass nextFromItem as fromItem, with the same sections, for the next part.	Not declared	Yes	Yes	Yes
`oeis_get_terms`List terms a(n) of a sequence with their indices n. Reads the entry's b-file when it has one — often thousands of terms beyond the data line — and otherwise the data line itself. Values are exact decimal strings of any size. A slice returns up to limit terms (at most 1000 per call) and may read the next b-file part to fill it. Pass nextFromIndex to continue.	List terms a(n) of a sequence with their indices n. Reads the entry's b-file when it has one — often thousands of terms beyond the data line — and otherwise the data line itself. Values are exact decimal strings of any size. A slice returns up to limit terms (at most 1000 per call) and may read the next b-file part to fill it. Pass nextFromIndex to continue.	Not declared	Yes	Yes	Yes
`oeis_identify_sequence`Identify integer sequences that contain a run of consecutive terms, e.g. "1, 2, 5, 14, 42". Returns up to 10 matches per page in OEIS relevance order, each with the index n at which the supplied run begins. For the best hit rate supply about 6 terms and leave off the first one or two, since sources disagree on where a sequence starts. OEIS matches only the first terms of each entry (its data line, at most about 270 characters), not its b-file, so a run from far into a sequence is not found. Takes up to 60 terms, each an integer of at most 200 digits or the wildcard _ for one unknown term.	Identify integer sequences that contain a run of consecutive terms, e.g. "1, 2, 5, 14, 42". Returns up to 10 matches per page in OEIS relevance order, each with the index n at which the supplied run begins. For the best hit rate supply about 6 terms and leave off the first one or two, since sources disagree on where a sequence starts. OEIS matches only the first terms of each entry (its data line, at most about 270 characters), not its b-file, so a run from far into a sequence is not found. Takes up to 60 terms, each an integer of at most 200 digits or the wildcard _ for one unknown term.	Not declared	Yes	Yes	Yes
`oeis_list_reference`Look up OEIS vocabulary used by the other tools: keyword flags (nonn, core, tabl, cons, …), search syntax (prefixes, operators, wildcards, sort orders, paging window), and identifier conventions (A-numbers, legacy M/N numbers, offsets, b-files).	Look up OEIS vocabulary used by the other tools: keyword flags (nonn, core, tabl, cons, …), search syntax (prefixes, operators, wildcards, sort orders, paging window), and identifier conventions (A-numbers, legacy M/N numbers, offsets, b-files).	Not declared	Yes	Yes	No
`oeis_search_sequences`Search the OEIS using its query syntax: plain words, "quoted phrases", comma-separated terms, prefixes (keyword:, author:, name:, comment:, formula:, program:, xref:, id:), \| for OR, and a leading - to exclude. Returns up to 10 summaries per page. For identifying a sequence from its terms, oeis_identify_sequence is the direct route.	Search the OEIS using its query syntax: plain words, "quoted phrases", comma-separated terms, prefixes (keyword:, author:, name:, comment:, formula:, program:, xref:, id:), \| for OR, and a leading - to exclude. Returns up to 10 summaries per page. For identifying a sequence from its terms, oeis_identify_sequence is the direct route.	Not declared	Yes	Yes	Yes

Details

Registry status: Active
Published: Nov 11, 2026
Updated: Nov 11, 2026
Website: Not given
Repository: https://github.com/cyanheads/oeis-mcp-server⁠ (opens in a new tab)
Categories: Uncategorized
GDPR: Not declared

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