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Search: id:A141336
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| A141336 |
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Primes of the form 2*x^2+6*x*y-7*y^2 (as well as of the form 2*x^2+10*x*y+y^2). |
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3
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| 2, 13, 29, 41, 73, 101, 173, 193, 197, 233, 257, 269, 277, 317, 349, 353, 397, 409, 449, 461, 509, 541, 577, 593, 601, 653, 673, 761, 809, 821, 829, 853, 857, 877, 929, 997
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OFFSET
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1,1
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COMMENT
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Discriminant = 92. 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(2)=13 because we can write 13=2*2^2+6*2*1-7*1^2 (or 13=2*1^2+10*1*1+1^2).
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CROSSREFS
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Cf. A141337 (d=92).
Sequence in context: A033837 A041575 A042917 this_sequence A031414 A030452 A132602
Adjacent sequences: A141333 A141334 A141335 this_sequence A141337 A141338 A141339
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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 25 2008
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