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A142956
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Primes of the form -3*x^2+4*x*y+5*y^2 (as well as of the form 6*x^2+10*x*y+y^2).
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1
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5, 17, 61, 73, 101, 137, 149, 157, 197, 229, 233, 277, 313, 349, 353, 389, 397, 457, 461, 541, 557, 577, 593, 613, 617, 653, 701, 709, 733, 757, 761, 769, 809, 821, 853, 881, 929, 937, 997
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Discriminant = 76. Class = 2. 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
| Borevich and Shafaewich, Number Theory.
D. B. Zagier, Zetafunktionen und quadratische Koerper.
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EXAMPLE
| a(2)=17 because we can write 17=-3*3^2+4*3*2+5*2^2 (or 17=6*1^2+10*1*1+1^2).
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CROSSREFS
| Cf. A142955 (d=76). A038872 (d=5). A141131 (d=8). A141122, A141123 (d=12). A038883 (d=13). A038889 (d=17). A141111, A141112 (d=65).
Sequence in context: A149661 A146130 A026619 * A192146 A007483 A149662
Adjacent sequences: A142953 A142954 A142955 * A142957 A142958 A142959
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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 (laucabfer(AT)alum.us.es), Jul 14 2008
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