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Repunit: History & Measurement

In recreational mathematics, a repunit is a number like 11, 111, or 1111 that contains only the digit 1 — a more specific type of repdigit. The term stands for "repeated unit" and was coined in 1966 by Albert H. Beiler in his book Recreations in the Theory of Numbers.

Language: English [EN]
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Repunit topic overview

The analysis highlights History and Measurement as prominent areas in the source structure around Repunit.

Related topics
45
Source areas
6
Connected nodes
51
Extracted relationships
166
Concept neighborhoods
27
Bridge connections
51

What this topic covers Research coverage

Source areas are shown by the number of related topics found in each part of the analysis. Use smaller areas too: they can reveal specialized angles and content gaps.

Repunit primes · 15 topics
Overview · 9 topics
Properties · 8 topics
Definition · 5 topics
Demlo numbers · 4 topics
History · 4 topics

Smaller areas are not necessarily less important. They contain fewer connections in this analysis and can be useful for finding specialized angles or coverage gaps.

Key facts & relationships

High-confidence facts extracted from structured source data. Use them as anchors for further research.

Conjectured no. of terms
Infinite
First terms
11, 1111111111111111111, 11111111111111111111111
Largest known term
(108177207−1)/9
No. of known terms
11
OEIS index
A004022 · Primes of the form (10^n − 1)/9

Explore all related topics Closing gaps

Browse the complete topic structure, not only the most central items. Less prominent entities and concepts can reveal missing angles, specialized context and useful research gaps. Each item opens a new analysis centered on that subject.

Overview

Definition

Properties

Repunit primes

History

Demlo numbers

Advanced semantic analysis

Deeper signals for content research, entity SEO and topical coverage. The plain-language headings explain what each technical view is useful for.

How Repunit connects Entity context

The extracted context around Repunit shows recurring relationship patterns in the source. For example, Repunit → Albert, AMS Chelsea Publishing, Another Look, Beiler, Bombay, Computers, Cresse, Delray Beach, Demlo, Devlali, Divisibility, Dover Publications, Dover Recreational Math, FL, History, India, ISBN, Journal, Kaprekar, KhareswadaRibenboim Another extracted example is Repunit → Any, As, Because, Carmichael, Euclidean Algorithm, For, If, It, Now, R1, R29, R35, Rd, Ri, Rj, Rm, Rn, Rp, Rq, Similarly. Use these groups to spot repeated connection types before inspecting the individual relationships.

Repunit

Top relations

related to References · 52
Repunit → Albert, AMS Chelsea Publishing, Another Look, Beiler, Bombay, Computers, Cresse, Delray Beach, Demlo, Devlali, Divisibility, Dover Publications, Dover Recreational Math, FL, History, India, ISBN, Journal, Kaprekar, KhareswadaRibenboim
related to Properties · 30
Repunit → Any, As, Because, Carmichael, Euclidean Algorithm, For, If, It, Now, R1, R29, R35, Rd, Ri, Rj, Rm, Rn, Rp, Rq, Similarly
related to Decimal repunit primes · 20
Repunit → A004023, April, As, It, Maksym Voznyy, May, Nth, OEIS, On July, On March, On May, R109297, R270343, R49081, R5794777, R8177207, R86453, Rn, Ryan Propper, Serge Batalov
related to history · 15
Repunit → Although, By, It, Kraitchik, Lehmer, Lucas, Oscar Hoppe, R16, R17, R19, R23, R36, Reuschle, Tables, The American
related to External links · 14
Repunit → Andy StewardRepunit Primes Project, Chris Caldwell, Cunningham, Eric, Giovanni Di Maria's, MathWorld, Of Numbers, Prime, Repunits, Smallest, The, The Prime Pages, Weisstein, World
related to Demlo numbers · 11
Repunit → A002477, Bombay, Demlo, Dombivili, He, Kaprekar, OEIS, Railway, The, They, Wonderful Demlo
related to Algebra factorization of generalized repunit numbers · 6
Repunit → Another, If, It, R2, R3, Rp
related to Repunit primes · 4
Repunit → It, Ra, Rn, The
related to Definition · 3
Repunit → Rn, The, Thus
OEIS index · 2
Repunit → A004022, Primes of the form (10^n − 1)/9

Important terminology

Use these terms to understand the vocabulary surrounding the topic, not as a checklist for keyword stuffing.

Important terminology

prime repunits numbers number rn primes displaystyle base base-b demlo form power probable known generalized also example factorization decimal 11

Repunit relationships Subject–Predicate–Object triples

TTTA extracted 166 structured relationships around Repunit. Examples in this analysis include Repunit → Conjectured no. of terms → Infinite and Repunit → First terms → 11, 1111111111111111111, 11111111111111111111111. The table shows each extracted connection, where it came from and its confidence.

SubjectPredicateObjectConfidenceSrc
RepunitConjectured no. of termsInfinite1.00infobox
RepunitFirst terms11, 1111111111111111111, 111111111111111111111111.00infobox
RepunitLargest known term(108177207−1)/91.00infobox
RepunitNo. of known terms111.00infobox
RepunitOEIS indexA0040221.00infobox
RepunitOEIS indexPrimes of the form (10^n − 1)/91.00infobox
Repunitis anumber like 110.90text
Repunitrelated to Algebra factorization of generalized repunit numbersIf0.60section
Repunitrelated to Algebra factorization of generalized repunit numbersRp0.60section
Repunitrelated to Algebra factorization of generalized repunit numbersR20.60section
Repunitrelated to Algebra factorization of generalized repunit numbersAnother0.60section
Repunitrelated to Algebra factorization of generalized repunit numbersR30.60section

Related concept clusters Concept neighborhoods

The concept neighborhoods around Repunit bring nearby vocabulary together. In this analysis, examples include Power, Numbers and Base. Use the clusters to find adjacent concepts and terminology that may deserve separate research.

  • number
    • Repunit
    • Digit
    • Form
    • Numbers
    • Prime
    • Repunits
    • Displaystyle
    • Base
    • Largest
    • Base-b
    • Decimal
    • Generalized
  • prime number
    • Repunit
    • Digit
    • Form
    • Numbers
    • Prime
    • Repunits
    • Displaystyle
    • Base
    • Primes
    • Largest
    • Base-b
    • Decimal
  • mersenne primes
    • Factorization
    • Generalized
    • Repunit
    • Conjecture
    • Many
    • Decimal
    • Repunits
    • Base-b
    • Base
    • Numbers
    • Largest
    • One
  • largest known prime number
    • Known
    • Largest
    • Repunit
    • Conjecture
    • Factorization
    • Generalized
    • Digit
    • Form
    • Numbers
    • Prime
    • Probable
    • Repunits
  • probable prime
    • Repunit
    • Repunits
    • Numbers
    • Found
    • Primes
    • Base-b
    • Example
    • Form
    • Probable
    • Rn
    • Also
    • Displaystyle
  • decimal
    • Conjecture
    • Digit
    • Generalized
    • Thus
    • Primes
    • Base
    • Repunit
    • Number
    • Base-b
    • Largest
    • Oeis
    • Repunits
  • goormaghtigh conjecture
    • Largest
    • Primes
    • Decimal
    • Factorization
    • Generalized
    • One
    • Displaystyle
    • Form
    • Base
    • Numbers
    • Base-b
    • Oeis
  • relatively prime
    • Repunit
    • Repunits
    • Numbers
    • Primes
    • Base-b
    • Example
    • Form
    • Probable
    • Rn
    • Also
    • Found
    • Displaystyle

Connections between topic areas Semantic bridges

For Repunit, one of the stronger structural bridges in this analysis connects Repunit with Repunit primes. Bridges highlight paths between different parts of the map and can reveal research angles that are easy to miss in a flat list.

Min side: 3
RepunitRepunit primes · splits 36 ⟂ 16
RepunitOverview · splits 42 ⟂ 10
RepunitProperties · splits 43 ⟂ 9
RepunitDefinition · splits 46 ⟂ 6
RepunitHistory · splits 47 ⟂ 5
RepunitDemlo numbers · splits 47 ⟂ 5

Map overview Semantic statistics

Repunit

Nodes52
Edges51
Triples166
Avg. degree1.96
Density0.038462
Components1

Source & methodology

TTTA analyzes the structure around Repunit to surface related topics, entities, relationships, concept neighborhoods and bridge connections. Use the map to explore areas such as History & Measurement, including less central topics that may reveal useful research gaps. Automatically extracted connections are research leads rather than rewritten encyclopedia content.

Source: Wikipedia — Repunit · EN edition · Analysis: TopicsToTalkAbout

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