|
Search: id:A141303
|
|
|
| A141303 |
|
Primes of the form 2*x^2+6*x*y-3*y^2 (as well as of the form 5*x^2+10*x*y+2*y^2). |
|
+0
8
|
|
| 2, 5, 17, 53, 113, 137, 173, 197, 233, 257, 293, 317, 353, 557, 593, 617, 653, 677, 773, 797, 857, 953, 977
(list; graph; listen)
|
|
|
OFFSET
|
0,1
|
|
|
COMMENT
|
Discriminant = 60. 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
|
|
REFERENCES
|
Borevich and Shafaewich, Number Theory.
D. B. Zagier, Zetafunktionen und quadratische Koerper.
|
|
EXAMPLE
|
a(3)=17 because we can write 17=2*2^2+6*2*1-3*1^2 (or 17=5*1^2+10*1*1+2*1^2).
|
|
CROSSREFS
|
Cf. A141301, A141302, A141304 (d=60).
Sequence in context: A148405 A148406 A148407 this_sequence A133510 A148408 A002692
Adjacent sequences: A141300 A141301 A141302 this_sequence A141304 A141305 A141306
|
|
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 24 2008
|
|
|
Search completed in 0.002 seconds
|
