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A028785
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Nonsquares mod 72.
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1
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2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23, 24, 26, 27, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 41, 42, 43, 44, 45, 46, 47, 48, 50, 51, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 65, 66, 67, 68, 69, 70, 71
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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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x^2 = 27 mod 72 has no solutions, so 27 is in the sequence.
x^2 = 28 mod 72 has the following solutions: x = 10, x = 26, x = 46, x = 62. So 28 is not in the sequence.
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MATHEMATICA
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Complement[Range[71], PowerMod[Range[71], 2, 72]] (* Alonso del Arte, Jan 14 2017 *)
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PROG
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(Scala) (0 to 71).diff((1 to 72).map(n => (n * n) % 72)) // Alonso del Arte, Dec 24 2019
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CROSSREFS
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KEYWORD
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nonn,fini,full,easy
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AUTHOR
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STATUS
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approved
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