A180008 Numbers n such that x^n + 2x + 1 is irreducible over GF(3).

0, 3, 5, 13, 17, 41, 51, 73, 121, 137, 485, 925, 2211

Offset

1,2

Links

Table of n, a(n) for n=1..13.

Mathematica

k = 0; lst = {}; While[k < 3001, If[ IrreduciblePolynomialQ[x^k + 2 x + 1, Modulus -> 3], AppendTo[lst, k]]; k++ ]; lst

Prog

(PARI) is(k) = polisirreducible(Mod(1, 3)*(x^k + 2*x + 1)); \\ Jinyuan Wang, Apr 15 2020

Crossrefs

Sequence in context: A040158 A147490 A266234 * A089996 A307512 A080076

Adjacent sequences: A180005 A180006 A180007 * A180009 A180010 A180011

Keyword

nonn,more

Author

Robert G. Wilson v, Aug 06 2010

Status

approved