# `OEIS`

A client for the [On-Line Encyclopedia of Integer Sequences (OEIS)](https://oeis.org).

# `fetch_more_terms`

Fetches extended sequence terms from the associated b-file.

Parses the linked b-file (e.g., `b000001.txt`) to extract additional terms, replacing the existing `data` field.
It also extracts any comments within the b-file and appends them to the sequence's `comment` list,
annotated with their line numbers (e.g., `[b-file L10] comment`).

## Options

* `:timeout` (integer): Request timeout in milliseconds (default: 15,000).

## Returns

* `{:ok, updated_sequence}`: Success.
* `{:error, %{original_sequence: seq, message: msg}}`: Failure.

## Examples

    iex> {:single, seq} = OEIS.search("A000001")
    iex> {:ok, updated} = OEIS.fetch_more_terms(seq)

# `fetch_xrefs`

Fetches sequences referenced in the `xref` field concurrently.

## Options

* `:timeout` (integer): Request timeout in milliseconds (default: 15,000).
* `:max_concurrency` (integer): Concurrency limit for parallel tasks (default: 5).
* `:stream` (boolean): If `true`, returns an Elixir Stream that lazily fetches and emits results (default: `false`).

## Returns

* `[sequence]`: List of successfully fetched `OEIS.Sequence` structs.
* `Enumerable.t()`: A stream of `OEIS.Sequence` structs if `stream: true`.

## Examples

    iex> {:single, seq} = OEIS.search("A000045")
    iex> refs = OEIS.fetch_xrefs(seq)

# `search`

Searches the OEIS database for sequences.

The first argument can be:
* A string ID (e.g., `"A000055"`).
* A list of integers (e.g., `[1, 2, 3, 5, 8]`).
* A string of integers (e.g., `"1, 2, 3, 5, 8"` or `"1 2 3 5 8"`).
* A keyword list of search parameters (see below).

## Options

* `:may_truncate` (boolean): If `true` (default), truncates the provided terms and removes leading 0s/1s to increase the chances of a match.
* `:respect_sign` (boolean): If `true` (default), respects signs. If `false`, ignores signs.
* `:timeout` (integer): Request timeout in milliseconds (default: 15,000).
* `:max_concurrency` (integer): Limit for parallel tasks (default: 5).
* `:start` (integer): Starting index for results (default: 0).
* `:stream` (boolean): If `true`, returns an Elixir Stream that lazily fetches and emits results (default: `false`).

## Parameters (Keyword List)

* `:sequence` (list/string): Terms to search for.
* `:id` (string): OEIS A-number.
* `:keyword` (string): Filter keyword (e.g., `"core"`).
* `:author` (string): Author name (automatically wildcards: `*name*`).
* `:query` (string): General query string.

## Returns

* `{:single, sequence}`: Exact ID match.
* `{:multi, [sequence]}`: Multiple matches found.
* `{:partial, [sequence]}`: Partial results (more likely available).
* `{:no_match, message}`: No results found.

## Examples

    iex> OEIS.search("A000045")
    {:single, %OEIS.Sequence{id: "A000045", ...}}

    iex> OEIS.search([1, 2, 3, 5, 8])
    {:multi, [%OEIS.Sequence{id: "A000045", ...}]}

    iex> OEIS.search(author: "Sloane", keyword: "core", start: 10)
    {:partial, [...]}

    iex> OEIS.search(query: "partitions", stream: true)
    #Stream<...>

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*Consult [api-reference.md](api-reference.md) for complete listing*