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PROJECT EULER · #0677

Coloured Graphs

Statement only · UnsolvedOriginal problem ↗

Let g(n) be the number of undirected graphs with n nodes satisfying the following properties:

  • The graph is connected and has no cycles or multiple edges.
  • Each node is either red, blue, or yellow.
  • A red node may have no more than 4 edges connected to it.
  • A blue or yellow node may have no more than 3 edges connected to it.
  • An edge may not directly connect a yellow node to a yellow node.

For example, g(2)=5, g(3)=15, and g(4)=57.
You are also given that g(10)=710249 and g(100)919747298(mod1000000007).

Find g(10000)mod1000000007.

Write-up coming later

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