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A141111
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Primes of the form 4*x^2+x*y-4*y^2 (as well as of the form 4*x^2+9*x*y+y^2).
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48
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29, 61, 79, 101, 131, 139, 179, 181, 191, 199, 211, 251, 269, 311, 389, 419, 439, 491, 521, 569, 571, 599, 601, 641, 659, 701, 719, 751, 809, 829, 859, 881, 911, 919, 971, 991, 1031, 1039, 1049, 1069, 1091, 1109, 1171, 1231, 1249, 1291, 1301, 1361, 1381, 1429, 1439, 1459, 1481, 1499, 1511, 1531
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Discriminant = 65. Class = 2. Binary quadratic forms a*x^2+b*x*y+c*y^2 have discriminant d=b^2-4ac and and gcd(a,b,c)=1.
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REFERENCES
| D. B. Zagier, Zetafunktionen und quadratische Koerper.
Borevich and Shafaewich, Number Theory.
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LINKS
| Juan Arias-de-Reyna, Table of n, a(n) for n=1,...,10000
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EXAMPLE
| a(3)=79 because we can write 79=4*5^2+5*3-4*3^2 (or 79=4*2^2+9*2*3+3^2)
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CROSSREFS
| Cf. A141112.
Sequence in context: A042678 A042680 A132770 * A122114 A173032 A142047
Adjacent sequences: A141108 A141109 A141110 * A141112 A141113 A141114
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KEYWORD
| nonn
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AUTHOR
| Laura Caballero Fernandez, Lourdes Calvo Moguer, Maria Josefa Cano Marquez, Oscar Jesus Falcon Ganfornina and Sergio Garrido Morales (oscfalgan(AT)yahoo.es), Jun 04 2008, Jun 05 2008
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