OEIS

Mode: 🌐 Public · Domain: oeis.org

Search the Online Encyclopedia of Integer Sequences by keyword or pattern, and fetch full sequence detail by A-number. OEIS is the canonical reference for integer sequences in mathematics — every sequence has a unique Annnnnn id.

Commands

Command	Description
opencli oeis search <query>	Search OEIS sequences by keyword or numeric pattern
opencli oeis sequence <id>	Full OEIS sequence detail by A-number

Usage Examples

# Keyword search
opencli oeis search fibonacci
opencli oeis search "prime gaps" --limit 5

# Numeric pattern search (find sequences matching a prefix)
opencli oeis search "1,1,2,3,5,8"            # Fibonacci
opencli oeis search "2,3,5,7,11,13,17"       # primes

# Sequence detail (A-number round-trips from search)
opencli oeis sequence A000045                  # Fibonacci
opencli oeis sequence A000040                  # Primes
opencli oeis sequence A000041                  # Partitions

Output Columns

Command	Columns
search	rank, id, name, keywords, preview, author, created, url
sequence	id, name, keywords, preview, termCount, offset, author, created, revision, commentCount, formulaCount, referenceCount, xrefCount, linkCount, url

The id column round-trips between commands.

Options

search

Option	Description
query (positional)	Keyword or comma-separated terms
--limit	Max sequences (1–100, default: 10). OEIS' wire format returns 10 per page; the adapter paginates server-side until limit is satisfied or upstream runs out.

sequence

Option	Description
id (positional)	OEIS A-number (e.g. A000045). Full URLs (https://oeis.org/A000045) and lowercase (a000045) are accepted.

Notes

• id is always zero-padded to 6 digits (A000045, A000040) — OEIS' canonical form. Search responses have raw integers (number: 45); the adapter formats them into the canonical id.
• preview is the first 12 terms, comma-joined. The full term sequence can be hundreds of integers; we cap with (+N) suffix so rows stay scannable. Use sequence + the data API tier (not exposed here) for the full term stream.
• keywords is a comma-joined string, OEIS' raw format. Common keywords:
  • core — universally referenced
  • nice — pleasing / well-known
  • easy — easy to compute
  • nonn — non-negative
  • mult — multiplicative
  • cofr — continued-fraction ish
• offset is OEIS' notation for where the sequence begins ('0,4' means first term is at index 0, first term ≥ 2 is at index 4). Useful for sequences that start with 1, 1 and you need to know where the "interesting" terms are.
• commentCount / formulaCount / referenceCount / xrefCount / linkCount are integer counts of how rich the OEIS page is. The full graphs are not surfaced — they can be enormous (Fibonacci has 250 links).
• No API key required. OEIS' free service is generous; bursts → CommandExecutionError.
• Errors. Empty query / bad A-number / bad limit → ArgumentError; unknown id / no matches → EmptyResultError; transport / 429 / non-200 → CommandExecutionError.