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 A141339 Primes of the form -x^2+9*x*y+3*y^2 (as well as of the form 11*x^2+15*x*y+3*y^2). 2
 3, 11, 17, 23, 29, 53, 83, 89, 137, 167, 179, 197, 239, 251, 263, 269, 347, 353, 383, 389, 401, 449, 461, 491, 509, 557, 569, 587, 641, 647, 677, 719, 743, 761, 773, 797, 809, 821, 827, 863, 881, 911, 929, 941, 947, 953, 983, 1013, 1019, 1049, 1091, 1097 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Discriminant = 93. 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. REFERENCES Z. I. Borevich and I. R. Shafarevich, Number Theory. D. B. Zagier, Zetafunktionen und quadratische Koerper. LINKS EXAMPLE a(5)=29 because we can write 29=-1^2+9*1*2+3*2^2 (or 29=11*1^2+15*1*1+3*1^2). CROSSREFS Cf. A141338 (d=93). Sequence in context: A056983 A175073 A062284 * A069348 A165561 A038960 Adjacent sequences:  A141336 A141337 A141338 * A141340 A141341 A141342 KEYWORD nonn AUTHOR Laura Caballero Fernandez, Lourdes Calvo Moguer, Maria Josefa Cano Marquez, Oscar Jesus Falcon Ganfornina and Sergio Garrido Morales (oscfalgan(AT)yahoo.es), Jun 25 2008 EXTENSIONS More terms from Colin Barker, Apr 05 2015 STATUS approved

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Last modified October 29 18:30 EDT 2020. Contains 338067 sequences. (Running on oeis4.)