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A054018
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Squares mentioned in A054017.
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3
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9, 1, 16, 9, 25, 16, 25, 49, 16, 1, 64, 121, 36, 81, 64, 169, 64, 36, 100, 225, 64, 36, 121, 36, 169, 49, 361, 225, 1, 144, 441, 441, 144, 256, 400, 196, 64, 441, 1, 144, 361, 64, 400, 441, 729, 64, 196, 144, 729, 100, 841, 729, 25, 400, 256, 1225, 100, 729, 1225
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OFFSET
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1,1
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COMMENTS
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If Chowla's function of n read (modulo n) is a nonzero square, print this square.
Chowla's function (A048050) = sum of divisors of n except 1 and n.
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LINKS
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MATHEMATICA
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chowla[n_] := DivisorSigma[1, n] - n - 1; aQ[n_] := (c = chowla[n]) > 0 && IntegerQ @ Sqrt @ Mod[c, n]; Mod[chowla[#], #] & /@ Select[Range[1000], aQ] (* Amiram Eldar, Aug 28 2019 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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