A059006 Numbers k such that x^k + x^2 + 1 is irreducible over GF(7).

2, 3, 6, 9, 18, 65, 66, 287, 354, 1425, 3743, 5598

Offset

1,1

Comments

No terms == 1 (mod 3), as e.g. 2^k + 2^2 + 1 == 0 mod 7 when k == 1 (mod 3). - Robert Israel, Dec 22 2024

Links

Table of n, a(n) for n=1..12.

Maple

R:= NULL:
for k from 1 to 10000 do
 if Irreduc(x^k + x^2 + 1) mod 7 then R:= R, k fi
od:
R; # Robert Israel, Dec 22 2024

Crossrefs

Cf. A057460, A058857.

Sequence in context: A018679 A018741 A161704 * A011962 A060172 A193196

Adjacent sequences: A059003 A059004 A059005 * A059007 A059008 A059009

Keyword

nonn

Author

Robert G. Wilson v, Jan 16 2001

Extensions

2 inserted and more terms from Robert Israel, Dec 22 2024

Status

approved