# Kneser Arrays

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Start with a set of numbers, , and find all the subsets of a given size. For example, {1, 2, 3, 4} has six subsets of size 2: {1, 2}, {1, 3}, {1, 4], {2, 3}, {2, 4}, and {3, 4}. Consider {1, 2}—it shares 2 values with itself, 1 value with {1, 3}, and 0 values with {3, 4}. An array of the amount of intersection shows an interesting pattern.

Contributed by: Ed Pegg Jr (March 2011)
Open content licensed under CC BY-NC-SA

## Details

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## Permanent Citation

Ed Pegg Jr "Kneser Arrays"
http://demonstrations.wolfram.com/KneserArrays/
Wolfram Demonstrations Project
Published: March 7 2011

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