---
total_numbers: 50827792
total_sequences: 392541
total_properties: 69
---

# number.md — a catalogue of numbers

50827792 numbers · 392,541 sequences · 69 properties.

## How to use this site

- Numbers are at `/N` (e.g. [/7](/7)).
- Sequences are at `/seq/<canonical_id>` (e.g. `/seq/A000045` for Fibonacci, when present).
- Listings at `/_sequences` and `/_properties`.
- All pages serve `text/plain` by default; pass `?raw=md` or `Accept: text/markdown` for the strong MIME type.

## Sample numbers

- [0](/0)
- [1](/1)
- [2](/2)
- [3](/3)
- [5](/5)
- [7](/7)
- [10](/10)
- [12](/12)
- [13](/13)
- [17](/17)
- [42](/42)
- [100](/100)