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Search: id:A141301
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| A141301 |
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Primes of the form x^2+6*x*y-6*y^2 (as well as of the form x^2+8*x*y+y^2). |
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+0
8
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| 61, 109, 181, 229, 241, 349, 409, 421, 541, 601, 661, 709, 769, 829
(list; graph; listen)
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OFFSET
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1,1
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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(2)=109 because we can write 109=7^2+6*7*2-6*2^2 (or 2^2+8*2*5+5^2).
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CROSSREFS
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Cf. A141302, A141303, A141304 (d=60).
See also A038872 (d=5).
A141131 (d=8).
A141122, A141123 (d=12).
A038883 (d=13).
A038889 (d=17).
A141158 (d=20).
A141159, A141160 (d=21).
A141170, A141171 (d=24).
A141172, A141173 (d=28).
A141174, A141175 (d=32).
A141176, A141177 (d=33).
A141178 (d=37).
A141179, A141180 (d=40).
A141181 (d=41).
A141182, A141183 (d=44).
A141184, A141185 (d=45).
A141122, A141187 (d=48).
A141188 (d=52).
A141189 (d=53).
A141190, A141191 (d=56).
A141192, A141193 (d=57).
A141215 (d=61).
A141111, A141112 (d=65).
A141161, A141162, A141163 (d=148).
A141164, A141165, A141166 (d=229).
A141167, A141167, A141167 (d=257).
Sequence in context: A086126 A023287 A141919 this_sequence A107152 A139898 A140009
Adjacent sequences: A141298 A141299 A141300 this_sequence A141302 A141303 A141304
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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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