# Sierpinski number

> English word · Noun

## Definitions
1. An odd natural number k such that k×2ⁿ+1 is composite for all natural numbers n.

## Etymology
Named after Polish mathematician Wacław Sierpiński.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/sierpinski-number