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A028739
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Nonsquares mod 26.
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1
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2, 5, 6, 7, 8, 11, 15, 18, 19, 20, 21, 24
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refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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LINKS
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EXAMPLE
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Since 2 is not a perfect square and there are no solutions to x^2 = 2 mod 26, 2 is in the sequence.
Although 3 is not a perfect square either, there are solutions to x^2 = 3 mod 26, such as x = 9, x = 17, 3 is not in the sequence.
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MATHEMATICA
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Complement[Range[0, 25], PowerMod[Range[0, 25], 2, 26]] (* Alonso del Arte, Nov 26 2019 *)
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PROG
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(Scala) val squaresMod26 = (0 to 25).map(n => n * n).map(_ % 26)
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CROSSREFS
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KEYWORD
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nonn,fini,full
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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