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A106906
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Primes of the form 2x^2-2xy+7y^2, with x and y nonnegative.
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2
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2, 7, 11, 19, 31, 47, 59, 67, 71, 83, 151, 163, 167, 223, 227, 239, 271, 307, 331, 359, 379, 383, 431, 463, 479, 487, 499, 587, 619, 631, 643, 683, 691, 739, 743, 787, 811, 827, 839, 863, 947, 967, 983, 1019, 1051, 1087, 1103, 1123, 1151, 1163, 1259, 1279
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Discriminant=-52. See A106856 for more information.
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FORMULA
| The primes are congruent to {2, 7, 11, 15, 19, 31, 47} (mod 52). - T. D. Noe (noe(AT)sspectra.com), May 02 2008
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MATHEMATICA
| f[x_, y_]:=2*x^2+2*x*y+7*y^2; lst={}; Do[Do[p=f[x, y]; If[PrimeQ[p], AppendTo[lst, p]], {y, -5!, 6!}], {x, -5!, 6!}]; Take[Union[lst], 5! ] [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Jul 06 2009]
QuadPrimes[2, -2, 7, 10000] (* see A106856 *)
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CROSSREFS
| Cf. A139827.
Sequence in context: A178899 A023393 A084619 * A106905 A103802 A097159
Adjacent sequences: A106903 A106904 A106905 * A106907 A106908 A106909
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KEYWORD
| nonn,easy
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AUTHOR
| T. D. Noe (noe(AT)sspectra.com), May 09 2005
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