Recent content by PCM72

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    Graduate Number of quadratic residues mod N>1

    UPDATE: Sorry, yesteday I made another mistake: the formula would work only for k=2 (i.e. as in the samples I used). This is the correct formula...
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    Graduate Number of quadratic residues mod N>1

    Hi. I hope you are still interested though I had wrongly understood that you meant the number of "all" quadratic residues modulo n, i.e. the squares mod N, while you wrote "invertible squares modulo N", writing also x\in(\mathbb{Z}/N)^\times, and then you meant the quadratic residues such that...
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    Graduate Number of quadratic residues mod N>1

    Hi. I've tested your formula with Maple and it doesn't work: phi2true:= N-> nops({seq(i^2 mod N,i=1..N-1)}) : factorset2:= N-> selectremove(x->x[1]=2,ifactors(N)[2]) : factorset2(2^3*7^2*11^2); [[2, 3]], [[7, 2], [11, 2]] phi2false:= proc(N) local f,n,p,k : f:=...