Research any topic before you write.

Find related topics. | Discover entities. | See connections. | Build a topical map.

Johnson graph

In mathematics, Johnson graphs are a special class of undirected graphs defined from systems of sets. The vertices of the Johnson graph J ( n , k ) {\displaystyle J(n,k)} are the k {\displaystyle k} -element subsets of an n {\displaystyle n} -element set; two vertices are adjacent when the intersection of the two vertices (subsets) contains ( k − 1 )…

Graph-theoretic properties, Special cases & Johnson scheme

Use the mouse wheel or two fingers (on touchscreens) to zoom in and out of the map.

Research this topic

Explore the main themes, entities and connections around Johnson graph. Start with the topic map, then use the sections below for research and deeper semantic analysis.

Explore this topic

Start with a few of the strongest sections from the source topic. These are research directions, not a list of keywords you must use.

Key facts & relationships

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

Diameter
min ( k , n − k ) {\displaystyle \min(k,n-k)}
Edges
1 2 k ( n − k ) ( n k ) {\displaystyle {\frac {1}{2}}k(n-k){\binom {n}{k}}}
Named after
Selmer M. Johnson
Notation
J ( n , k ) {\displaystyle J(n,k)}
Properties
k ( n − k ) {\displaystyle k(n-k)} -regular Vertex-transitive Distance-transitive Hamilton-connected Polytopal
Vertices
( n k ) {\displaystyle {\binom {n}{k}}}

Topics to explore

Browse the full topic structure. Each item opens a new analysis centered on that subject.

Overview

Special cases

Graph-theoretic properties

Automorphism group

Intersection array

Eigenvalues and eigenvectors

Johnson scheme

Open problems

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.

Map overview Semantic statistics

Johnson graph

Nodes48
Edges47
Triples36
Avg. degree1.96
Density0.041667
Components1

How this topic connects Entity context

See the strongest relationship patterns around the current topic before diving into the raw triples.

Johnson graph

Top relations

related to Graph-theoretic properties · 11
Johnson graph → Any, Each Johnson, For, Hamilton-connected, Hamiltonian, In, It, Johnson, More, N-k, The
related to Special cases · 7
Johnson graph → Both, Johnson, K5, Kn, Kneser, More, Petersen
related to External links · 5
Johnson graph → Andries, Eric, Johnson, MathWorldBrouwer, Weisstein
related to Open problems · 4
Johnson graph → However, In, Johnson, The
related to Johnson scheme · 2
Johnson graph → Johnson, The Johnson
Diameter · 1
Johnson graph → min ( k , n − k ) {\displaystyle \min(k,n-k)}
Edges · 1
Johnson graph → 1 2 k ( n − k ) ( n k ) {\displaystyle {\frac {1}{2}}k(n-k){\binom {n}{k}}}
Named after · 1
Johnson graph → Selmer M. Johnson
Notation · 1
Johnson graph → J ( n , k ) {\displaystyle J(n,k)}
Properties · 1
Johnson graph → k ( n − k ) {\displaystyle k(n-k)} -regular Vertex-transitive Distance-transitive Hamilton-connected Polytopal

Important terminology Word statistics

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

Important terminology

displaystyle johnson graph graphs vertices scheme sets distance-transitive n-k number selmer intersection also properties pair given -element set related special

Entity relationships Subject–Predicate–Object triples

SubjectPredicateObjectConfidenceSrc
Johnson graphDiametermin ( k , n − k ) {\displaystyle \min(k,n-k)}1.00infobox
Johnson graphEdges1 2 k ( n − k ) ( n k ) {\displaystyle {\frac {1}{2}}k(n-k){\binom {n}{k}}}1.00infobox
Johnson graphNamed afterSelmer M. Johnson1.00infobox
Johnson graphNotationJ ( n , k ) {\displaystyle J(n,k)}1.00infobox
Johnson graphPropertiesk ( n − k ) {\displaystyle k(n-k)} -regular Vertex-transitive Distance-transitive Hamilton-connected Polytopal1.00infobox
Johnson graphVertices( n k ) {\displaystyle {\binom {n}{k}}}1.00infobox
Johnson graphis aopen problem0.90text
Johnson graphrelated to External linksWeisstein0.60section
Johnson graphrelated to External linksEric0.60section
Johnson graphrelated to External linksMathWorldBrouwer0.60section
Johnson graphrelated to External linksAndries0.60section
Johnson graphrelated to External linksJohnson0.60section

Related concept clusters Concept neighborhoods

These clusters group vocabulary that occurs around closely connected concepts in the source material.

    Connections between topic areas Semantic bridges

    Bridges can reveal useful research angles that are easy to miss in a flat list of related terms.

    Min side: 3
    For writers, content strategists, SEOs, marketers and creators — from quick topic research to advanced semantic analysis.