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A141376 Primes of the form -x^2+8*x*y+8*y^2 (as well as of the form 15*x^2+24*x*y+8*y^2). 4
23, 47, 71, 167, 191, 239, 263, 311, 359, 383, 431, 479, 503, 599, 647, 719, 743, 839, 863, 887, 911, 983, 1031, 1103, 1151, 1223, 1319, 1367, 1439, 1487, 1511, 1559, 1583, 1607, 1823, 1847, 1871, 2039, 2063, 2087, 2111, 2207, 2351, 2399, 2423, 2447, 2543 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Discriminant = -96. Class = 4. Binary quadratic forms a*x^2+b*x*y+c*y^2 have discriminant d=b^2-4ac and gcd(a,b,c)=1

Values of the quadratic form are {0,8,12,15,20,23} mod 24, so this is a subset of A134517. - R. J. Mathar, Jul 30 2008

Is this the same sequence as A134517?

REFERENCES

Z. I. Borevich and I. R. Shafarevich, Number Theory.

D. B. Zagier, Zetafunktionen und quadratische Koerper.

LINKS

Table of n, a(n) for n=1..47.

EXAMPLE

a(2)=47 because we can write 47=-1^2+8*1*2+8*2^2 (or 47=15*1^2+24*1*1+8*1^2).

CROSSREFS

Cf. A141373, A107003, A141375 (d = -96).

Sequence in context: A130063 A183010 A134517 * A140614 A001124 A139501

Adjacent sequences:  A141373 A141374 A141375 * A141377 A141378 A141379

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 28 2008

EXTENSIONS

More terms from Arkadiusz Wesolowski, Jul 25 2012

STATUS

approved

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Last modified September 19 04:39 EDT 2019. Contains 327187 sequences. (Running on oeis4.)