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Search: id:A141182
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| A141182 |
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Primes of the form x^2+6*x*y-2*y^2 (as well as of the form 5*x^2+8*x*y+y^2). |
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+0
8
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| 5, 37, 53, 89, 97, 113, 137, 157, 181, 229, 257, 269, 313, 317, 353, 389, 397, 401, 421, 433, 449, 509, 521, 577, 617, 641, 653, 661, 709, 757, 773, 797, 829, 881, 929, 977
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OFFSET
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1,1
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COMMENT
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Discriminant = 44. Class = 2. 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)=53 because we can write 53=5^2+6*5*1-2*1^2 (or 53=5*1^2+8*1*4+4^2)
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CROSSREFS
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Cf. A141183 (d=44) A038872 (d=5). A141131 (d=8). A141122, A141123 (d=12). A038883 (d=13). A038889 (d=17): A141111, A141112 (d=65).
Sequence in context: A106129 A096673 A071680 this_sequence A127589 A031913 A054587
Adjacent sequences: A141179 A141180 A141181 this_sequence A141183 A141184 A141185
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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 (lourdescm84(AT)hotmail.com), Jun 12 2008
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