{
  "aliases": [
    "dutch-windmill-graph",
    "n-fan"
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  "body": "\n## Summary\n\nIn the mathematical field of graph theory, the **friendship graph** (or **Dutch windmill graph** or **$n$-fan**) $F_{n}$ is a [[planar|029JQEK15B]], undirected graph with $2n + 1$ vertices and $3n$ edges.\n",
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  "markdown": "https://math2.tamnd.com/node/6F75HN0W6J.md",
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  "name": "Friendship graph",
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