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Search: id:A141304
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| A141304 |
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Primes of the form -2*x^2+6*x*y+3*y^2 (as well as of the form 7*x^2+12*x*y+3*y^2). |
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8
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| 3, 7, 43, 67, 103, 127, 163, 223, 283, 307, 367, 463, 487, 523, 547, 607, 643, 727, 787, 823, 883, 907, 967
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OFFSET
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0,1
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COMMENT
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Discriminant = 60. Class = 4. Binary quadratic forms a*x^2+b*x*y+c*y^2 have discriminant d=b^2-4ac and gcd(a,b,c)=1
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REFERENCES
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Borevich and Shafaewich, Number Theory.
D. B. Zagier, Zetafunktionen und quadratische Koerper.
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EXAMPLE
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a(3)=43 because we can write 43=-2*1^2+6*1*3+3*3^2 (or 43=7*1^2+12*1*2+3*2^2).
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CROSSREFS
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Cf. A141301, A141302, A141303 (d=60).
Sequence in context: A018993 A100837 A106965 this_sequence A101208 A050633 A107636
Adjacent sequences: A141301 A141302 A141303 this_sequence A141305 A141306 A141307
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KEYWORD
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nonn
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AUTHOR
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Laura Caballero Fernandez, Lourdes Calvo Moguer, Maria Josefa Cano Marquez, Oscar Jesus Falcon Ganfornina and Sergio Garrido Morales (oscfalgan(AT)yahoo.es), Jun 24 2008
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