login
This site is supported by donations to The OEIS Foundation.
Logo

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A106867 Primes of the form 2*x^2+x*y+3*y^2, with x and y any integer. 3
2, 3, 13, 29, 31, 41, 47, 71, 73, 127, 131, 139, 151, 163, 179, 193, 197, 233, 239, 257, 269, 277, 311, 331, 349, 353, 397, 409, 439, 443, 461, 487, 491, 499, 509, 541, 547, 577, 587, 601, 647, 653, 673, 683, 739, 761, 811, 823, 857, 859, 863, 887, 929, 947 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Discriminant=-23. See A106856 for more information.

Primes p such that the polynomial x^3-x-1 is irreducible over Zp. The polynomial discriminant is also -23. - T. D. Noe, May 13 2005

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

MATHEMATICA

Union[QuadPrimes[2, 1, 3, 10000], QuadPrimes[2, -1, 3, 10000]] (* see A106856 *)

PROG

(PARI) forprime(p=2, 10^4, if(0==#polrootsmod(x^3-x-1, p), print1(p, ", "))); /* Joerg Arndt, Jul 27 2011 */

(PARI) forprime(p=2, 10^4, if(polisirreducible(Mod(1, p)*(x^3-x-1)), print1(p, ", ") ) ); /* Joerg Arndt, Mar 30 2013 */

CROSSREFS

Cf. A086965 (number of distinct zeros of x^3-x-1 mod prime(n)).

Sequence in context: A105891 A141585 A191021 * A141861 A215379 A215375

Adjacent sequences:  A106864 A106865 A106866 * A106868 A106869 A106870

KEYWORD

nonn,easy

AUTHOR

T. D. Noe, May 09 2005

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Puzzles | Hot | Classics
Recent Additions | More pages | Superseeker | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified May 26 02:53 EDT 2013. Contains 225653 sequences.