Gapplet

Given an invertible 2×2 matrix with coefficients in Z/pZ, write down the permutation it induces on the p2-1 nonzero vectors.

Give a small prime p  
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Give a 2×2 matrix M with numbers in {0,...,p-1}, e.g.,  
[[1,1],[1,4]]
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The permutation in the answer is a list 
of the images of 1,...,p2-1 under M.
Here, the nonzero vector [i,j] is identified with i+p(j-1), where i and j are taken to lie in {1,...,p
(so 0 is replaced by p). 
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