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A243185
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Nonnegative numbers of the form -2*x^2+3*x*y+3*y^2.
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1
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0, 1, 3, 4, 9, 12, 16, 22, 25, 27, 31, 34, 36, 37, 48, 49, 58, 64, 66, 67, 75, 81, 82, 88, 93, 97, 100, 102, 103, 108, 111, 121, 124, 136, 144, 147, 148, 157, 163, 166, 169, 174, 181, 187, 192, 196, 198, 199, 201, 202, 214, 223, 225, 229, 232, 243, 246, 256, 262, 264, 268, 279, 289, 291, 298, 300
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OFFSET
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1,3
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COMMENTS
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Discriminant 33.
I do not understand why the Mathematica program misses out 0.
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LINKS
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Table of n, a(n) for n=1..66.
N. J. A. Sloane et al., Binary Quadratic Forms and OEIS (Index to related sequences, programs, references)
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MATHEMATICA
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Reap[For[n = 0, n <= 300, n++, If[Reduce[-2*x^2 + 3*x*y + 3*y^2 == n, {x, y}, Integers] =!= False, Sow[n]]]][[2, 1]]
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CROSSREFS
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For primes see A141177.
Sequence in context: A112169 A155564 A105137 * A336166 A230781 A025613
Adjacent sequences: A243182 A243183 A243184 * A243186 A243187 A243188
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane, Jun 04 2014
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STATUS
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approved
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