|
Search: id:A106872
|
|
|
| A106872 |
|
Primes of the form 2x^2+xy+4y^2, with x and y any integer. |
|
+0
2
|
|
| 2, 5, 7, 19, 41, 59, 71, 97, 101, 103, 107, 109, 113, 157, 163, 191, 193, 211, 233, 257, 281, 307, 311, 317, 359, 373, 397, 419, 421, 439, 443, 467, 479, 503, 541, 547, 563, 593, 599, 659, 661, 683, 691, 701, 727, 733, 751, 769, 877, 887, 907, 977, 997, 1033
(list; graph; listen)
|
|
|
OFFSET
|
1,1
|
|
|
COMMENT
|
Discriminant=-31. See A106856 for more information.
Primes p such that the polynomial x^3-x^2-1 is irreducible over Zp. The polynomial discriminant is also -31. - T. D. Noe (noe(AT)sspectra.com), May 13 2005
|
|
MATHEMATICA
|
f[x_, y_]:=2*x^2+x*y+4*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 04 2009]
Union[QuadPrimes[2, 1, 4, 10000], QuadPrimes[2, -1, 4, 10000]] (* see A106856 *)
|
|
CROSSREFS
|
Sequence in context: A042449 A046115 A089443 this_sequence A071198 A041387 A096146
Adjacent sequences: A106869 A106870 A106871 this_sequence A106873 A106874 A106875
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
T. D. Noe (noe(AT)sspectra.com), May 09 2005
|
|
|
Search completed in 0.002 seconds
|
