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Search: id:A141376
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| A141376 |
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Primes of the form -x^2+8*x*y+8*y^2 (as well as of the form 15*x^2+24*x*y+8*y^2). |
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+0
5
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| 23, 47, 71, 167, 191, 239, 263, 311, 359, 383, 431, 479, 503, 599, 647, 719, 743, 839, 863, 887, 911, 983
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Discriminant = 96. 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
Values of the quadratic form are {0,8,12,15,20,23} mod 24, so this is a subset of A134517. - R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Jul 30 2008
Is this the same sequence as A134517?
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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)=47 because we can write 47=-1^2+8*1*2+8*2^2 (or 47=15*1^2+24*1*1+8*1^2).
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CROSSREFS
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Cf. A141373, A141374, A141375 (d=96).
Sequence in context: A042044 A042042 A130063 this_sequence A134517 A140614 A001124
Adjacent sequences: A141373 A141374 A141375 this_sequence A141377 A141378 A141379
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KEYWORD
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nonn,more
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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 28 2008
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