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A141168
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Primes of the form 4*x^2+9*x*y-11*y^2.
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7
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2, 11, 13, 17, 23, 29, 31, 59, 73, 79, 89, 137, 139, 173, 199, 211, 223, 239, 283, 293, 307, 317, 349, 373, 379, 397, 401, 433, 457, 479, 491, 503, 523, 563, 571, 593, 613, 647, 673, 683, 701, 709, 719, 727, 769, 773, 787, 797, 829, 839, 887, 911, 967
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OFFSET
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1,1
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COMMENTS
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Discriminant = 257. 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
Also primes represented by the improperly equivalent form 11*x^2+9*x*y-4*y^2. - Juan Arias-de-Reyna, Mar 18 2011
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REFERENCES
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Z. I. Borevich and I. R. Shafarevich, Number Theory
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LINKS
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EXAMPLE
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a(5)=23 because we can write 23= 4*2^2+9*2*1-11*1^2
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CROSSREFS
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For a list of sequences giving numbers and/or primes represented by binary quadratic forms, see the "Binary Quadratic Forms and OEIS" link.
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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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STATUS
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approved
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