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 A141778 Primes of the form 4*x^2+3*x*y-5*y^2 (as well as of the form 8*x^2+11*x*y+y^2). 2
 2, 5, 11, 17, 47, 53, 67, 71, 73, 79, 89, 97, 107, 109, 131, 139, 157, 167, 173, 179, 199, 223, 227, 233, 251, 257, 263, 269, 271, 277, 283, 307, 311, 317, 331, 347, 367, 373, 401, 409, 443, 449, 461, 463, 467, 479, 487, 509, 523, 587, 601, 607, 613, 619, 631 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Discriminant = 89. Class = 1. Binary quadratic forms a*x^2+b*x*y+c*y^2 have discriminant d=b^2-4ac and gcd(a,b,c)=1. Is this the same as A038977? - R. J. Mathar, Jul 04 2008 A subsequence of (and may possibly coincide with) A038977. - R. J. Mathar, Jul 22 2008 REFERENCES Borevich and Shafaewich, Number Theory. D. B. Zagier, Zetafunktionen und quadratische Koerper. LINKS EXAMPLE a(1)=2 because we can write 2 = 4*1^2+3*1*1-5*1^2. CROSSREFS See also A038872 (d=5). A038873 (d=8). A068228, 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). A033212, A141785 (d=45). A068228, A141187 (d=48). A141188 (d=52). A141189 (d=53). A141190, A141191 (d=56). A141192, A141193 (d=57). A141301, A141302, A141303, A141304 (d=60). A141215 (d=61). A141111, A141112 (d=65). A141750 (d=73). A141772, A141773 (d=85). A141776, A141777 (d=88). A141778 (d=89). A141161, A141163 (d=148). A141165, A141166 (d=229). A141167, A141168 (d=257). Sequence in context: A174003 A144572 A038977 * A191053 A209493 A117877 Adjacent sequences:  A141775 A141776 A141777 * A141779 A141780 A141781 KEYWORD nonn AUTHOR Laura Caballero Fernandez, Lourdes Calvo Moguer, Maria Josefa Cano Marquez, Oscar Jesus Falcon Ganfornina and Sergio Garrido Morales (sergarmor(AT)yahoo.es), Jul 04 2008 EXTENSIONS Typo in crossrefs fixed by Colin Barker, Apr 05 2015 STATUS approved

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Last modified August 23 00:16 EDT 2017. Contains 290953 sequences.