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Search: id:A141162
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| A141162 |
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Primes of the form 7*x^2+6*x*y-4*y^2. |
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+0
9
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| 3, 7, 11, 41, 47, 53, 71, 73, 83, 101, 127, 149, 157, 173, 181, 197, 211, 223, 229, 263, 271, 307, 337, 359, 373, 379, 397, 419, 433, 443, 509, 521, 571, 593, 599, 613, 617, 619, 641, 659, 673, 677, 719, 733, 739, 743, 751, 761, 773, 787, 811, 821, 887, 937
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OFFSET
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1,1
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COMMENT
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Discriminant = 148. Class = 3. 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(9)=83 because we can write 83= 7*3^2+6*3*2-4*2^2
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CROSSREFS
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Cf. A038872 (d=5). A141131 (d=8). A141122, A141123 (d=12). A038883 (d=13). A038889 (d=17). A141111, A141112 (d=65). A141161, A141163 (d=148).
Adjacent sequences: A141159 A141160 A141161 this_sequence A141163 A141164 A141165
Sequence in context: A033871 A139599 A141161 this_sequence A005372 A125220 A016081
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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 (sergarmor(AT)yahoo.es), Jun 12 2008
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