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A242666
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Nonnegative integers of the form -x^2 + 4xy + 3y^2.
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3
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0, 3, 6, 7, 12, 14, 19, 24, 27, 28, 31, 38, 47, 48, 54, 56, 59, 62, 63, 75, 76, 83, 87, 94, 96, 103, 108, 111, 112, 118, 124, 126, 131, 139, 147, 150, 152, 159, 166, 167, 171, 174, 175, 188, 192, 199, 203, 206, 216, 222, 223, 224, 227, 236, 243, 248, 251, 252, 259, 262, 271, 278, 279, 283, 294, 300
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OFFSET
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1,2
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COMMENTS
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Discriminant 28.
For the subsequence of the numbers with proper representations (gcd(x, y) = 1) see A359476. ~ Wolfdieter Lang, Jan 17 2023
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LINKS
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MATHEMATICA
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Reap[For[n = 0, n <= 300, n++, If[Reduce[-x^2 + 4*x*y + 3*y^2 == n, {x, y}, Integers] =!= False, Sow[n]]]][[2, 1]]
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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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