ParseForge
OEIS Integer Sequences Scraper
parseforge/oeis-integer-sequences-scraper
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Scrapes OEIS integer sequences by search query, A-number list, or keyword filter. Returns each sequence as a flat row with optional comments, formulas, and extended terms.
- Total users
- 2
- Monthly active
- 1
- Total runs
- 123
- Bookmarked
- 0
- Rating
- Not rated yet
- Last modified
- 9 days ago
Overview
OEIS Integer Sequences Scraper
Scrape OEIS integer sequences by search term, A-number, or keyword, up to a million per run. Every sequence comes with its terms, name, and optional comments, formulas, references, and programs. Export to CSV, JSON, Excel, or XML.
The OEIS (On-Line Encyclopedia of Integer Sequences) holds over 350,000 curated integer sequences, but browsing the website means clicking through pages one at a time. This Actor reads the public search and detail pages directly, filters by author or keyword, and returns each match in one fixed schema. No API key or registration needed.
| Who uses it | What they scrape OEIS for |
|---|---|
| Mathematicians | Pull a batch of sequences that share a keyword or author for offline analysis. |
| Data scientists | Build a local dataset of integer sequences to train a sequence-completion model. |
| Recreational math enthusiasts | Grab the latest 'nice' or 'core' sequences to explore patterns. |
| Academic researchers | Collect all sequences by a specific contributor to study their body of work. |
What it does
This Actor collects OEIS integer sequences by search query, A-number list, or keyword filter, and returns each one as a flat row.
- 🔍 Search by name: free-text query across the sequence index, with multi-word AND matching.
- 🆔 Direct A-number lookup: pull one or many sequences by their exact A-number, like A000045.
- 🏷️ Keyword filter: restrict results to sequences tagged 'core', 'nice', 'easy', 'hard', and 30 other OEIS keywords.
- ✍️ Author filter: case-insensitive substring match on the sequence author field.
- 📊 Enriched details: optionally fetch comments, references, formulas, programs, and the full author name.
- 📈 Extended terms: replace the default ~80 terms with the full term list, often hundreds or thousands of integers.
Results export to CSV, JSON, Excel, or XML, or straight from the API.
What you can do with OEIS data
🔢 Build a local OEIS mirror.
A researcher runs the Actor with maxItems set to 1,000,000 and no filters to download the entire public index for offline querying.
🧪 Collect training data for a sequence model.
A data scientist scrapes all 'core' and 'nice' sequences with extended terms to create a dataset for a machine learning model that predicts the next integer.
📚 Study one author's contributions.
A math historian filters by author 'Sloane' and fetches details to compile a bibliography of sequences submitted by the OEIS founder.
🎯 Pull a specific set of sequences by A-number.
A teacher pastes a list of A-numbers from a lesson plan and collects the terms and names for a classroom handout.
Why choose this scraper
| What you get | |
|---|---|
| Batch collection | Pull up to a million sequences in one run instead of clicking through the website. |
| Fixed schema | Every sequence lands as a flat row with the same fields, ready for analysis. |
| Optional enrichment | Add comments, formulas, and programs only when you need them, saving time on large runs. |
| Flexible input | Search by name, fetch by A-number, or filter by keyword and author in any combination. |
How it compares
No other Store actor targets OEIS the same way, so the honest comparison is with the alternatives teams actually weigh.
| OEIS Integer Sequences Scraper | Build it in-house | By hand | |
|---|---|---|---|
| Setup | Run it now, zero config | Days of engineering | None, but hours per pull |
| When OEIS changes | Maintained for you | You fix it | You re-learn the page |
| Proxies, retries, anti-bot | Built in | Your problem | Browser only |
| Output | Fixed JSON schema, CSV/Excel export | Whatever you build | Copy-paste |
| Cost | Pay per result | Engineering time | Analyst hours |
Configure the run
Drive the Actor from a search query, a list of A-numbers, or both, and apply keyword and author filters as each sequence is read so only matches reach your dataset. The Input tab lists every parameter.
A first run with the defaults:
{
"maxItems": 10,
"searchQuery": "fibonacci"
}
A larger pull:
{
"maxItems": 200,
"searchQuery": "fibonacci"
}
Pricing
Pay-per-result: $0.012 per result collected. You pay only for the results written to your dataset.
| Results collected | Approximate cost |
|---|---|
| 100 results | $1.20 |
| 1,000 results | $12.00 |
| 10,000 results | $120.00 |
New Apify accounts start with $5 in free credit.
Free users
Free-plan runs return up to 10 results as a preview. Upgrade your Apify plan to collect up to 1,000,000 results per run.
Run it
- Create a free Apify account with $5 in credit.
- Open the OEIS Integer Sequences Scraper.
- Set your inputs and any filters, then click Start.
- Export the results as CSV, Excel, JSON, or XML from the Dataset tab.
Run it programmatically through the Apify API (run-sync-get-dataset-items) or the ApifyClient for JavaScript and Python.
Use with AI agents (MCP)
Give an AI agent live access to OEIS through the Model Context Protocol. Add the Actor to Claude, Cursor, or any MCP client:
claude mcp add --transport http apify "https://mcp.apify.com?tools=parseforge/oeis-integer-sequences-scraper"
Then prompt it in plain language to run the scraper and read back the results.
Troubleshooting
Why am I getting no results?
Check that your search query or A-number list is not empty. If you are using keyword or author filters, try removing them to see if results appear. Also verify that the A-number format is correct, like A000045.
Why are some sequences missing comments or formulas even with Fetch Details on?
Not every OEIS entry has comments, formulas, or programs. The Actor returns whatever is present on the detail page. An empty field means the sequence author did not provide that content.
The run is taking a long time with Fetch Details enabled.
Fetch Details adds one request per sequence. For large runs, disable it and only enable it for smaller, targeted collections. You can also reduce the Maximum Sequences count.
My keyword filter returns fewer sequences than expected.
Keyword filters use AND logic. If you select 'core' and 'nice', only sequences tagged with both keywords are returned. Try selecting fewer keywords to broaden the results.
FAQ
| Question | Answer |
|---|---|
| How do I get a single sequence by its A-number? | Set the A-Number List field to the exact A-number, like A000045. That overrides any search query and returns only that sequence. |
| What is the difference between terms and extended terms? | By default the Actor returns about 80 terms. When you enable Extended Terms, it fetches the full term list, which can be hundreds or thousands of integers long. |
| Does Fetch Details slow down the run? | Yes, it adds one extra request per sequence to load the detail page. For large runs, leave it off unless you need comments, formulas, or programs. |
| Can I filter by more than one keyword? | Yes, select multiple keywords in the Sequence Keywords list. Only sequences that match all selected keywords are returned. |
| How do I search for sequences about prime numbers? | Enter 'prime' in the Search Term field. Multi-word queries like 'prime numbers' are AND-matched, so both words must appear in the sequence name. |
| What output formats are supported? | You can export your dataset to CSV, JSON, Excel, or XML from the Apify platform after the run finishes. |
| Is there a rate limit on the OEIS website? | The Actor respects the public website's structure and paces requests to avoid overloading the server. No API key is required. |
| Can I get sequences that were recently added or changed? | Yes, select the 'new' or 'changed' keyword in the Sequence Keywords filter to target recently updated entries. |
| What happens if I set both a search query and an A-number list? | The A-Number List takes priority and the search query is ignored. Use one or the other for predictable results. |
| How many sequences can I collect in one run? | You can set the Maximum Sequences field up to 1,000,000. The actual number collected depends on how many match your filters. |
Related actors
Browse the full ParseForge collection for more scrapers.
🆘 Need help? Email parseforge@protonmail.com with your run ID, your input, and what you expected.
⚠️ Disclaimer. This Actor is unofficial and is not affiliated with, endorsed by, or sponsored by OEIS Foundation Inc. It collects only publicly available data. You are responsible for using the collected data in compliance with the source's terms of service and applicable data-protection laws, including GDPR, CCPA, and PIPL. Do not use it to collect personal data unlawfully.
Input
| Field | Type | What it does | Default |
|---|---|---|---|
| maxItems | integer | Maximum number of integer sequences to collect per run. | 10 |
| searchQuery | string | Free-text search across the sequence index. Multi-word queries are AND-matched. Use 'id:A000045' to pull a single sequence by A-number. | fibonacci |
| aNumbers | array | Exact A-number list (e.g. 'A000045', 'A000040'). Overrides searchQuery when set. | not set |
| keywords | array | Keyword filter (all selected keywords must match). Enabling this automatically turns on Fetch Details. | not set |
| author | string | Case-insensitive author substring match (e.g. 'Sloane'). Enabling this automatically turns on Fetch Details. | not set |
| sortBy | string (3 options) | Order of returned sequences. 'a_number_asc' = lowest A-number first. 'a_number_desc' = highest first. 'relevance' = best name match first. | a_number_asc |
| fetchDetails | boolean | Add comments, references, formulas, programs, keywords, and author for each match. Adds 1 fetch per item. | false |
| extendedTerms | boolean | Replace 'terms' with the full extended term list (hundreds to thousands vs the default ~80). Adds 1 fetch per item. | false |
Pricing
from $9.00 per 1,000 results
| Charged for | What it is | Price each |
|---|---|---|
| Result Item | Charged once per result collected. | $0.009 to $0.012 |
Tiered: the lower figure is the price on a higher Apify plan. Billing and the free credit live on Apify.
API
One POST returns the dataset directly. Same shape for every scraper in the library, so swapping the slug is the only change.
curl -X POST "https://api.apify.com/v2/acts/parseforge~oeis-integer-sequences-scraper/run-sync-get-dataset-items?token=$APIFY_TOKEN" \
-H "Content-Type: application/json" \
-d '{
"helloWorld": 123
}' Examples
Input that runs as-is.
{
"helloWorld": 123
} Reviews
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Issues
We build and maintain this scraper, so a problem with it comes to us. Report it on the Apify listing and the thread stays attached to the scraper where the next person can find it: open an issue.
Broken and urgent, or you would rather not post in public? Write to parseforge@protonmail.com and it reaches the people who wrote it.