A057479 Numbers k such that x^k + x^9 + 1 is irreducible over GF(2).

1, 4, 5, 8, 11, 12, 14, 18, 23, 28, 30, 36, 49, 54, 60, 68, 71, 79, 84, 103, 113, 151, 156, 191, 198, 364, 390, 470, 476, 508, 540, 620, 721, 823, 865, 1135, 1558, 1825, 1950, 4225, 4788, 8100, 12294, 12553, 14686, 18516, 19660, 24470, 30486, 32086, 43908

Offset

1,2

Comments

The b-file contains all terms <= 300000. - Lucas A. Brown, Nov 28 2022

Links

Lucas A. Brown, Table of n, a(n) for n = 1..67

Lucas A. Brown, Python program.

Lucas A. Brown, Sage program.

Maple

select(n  -> Irreduc(x^n + x^9 + 1) mod 2, [$1..1000]); # Robert Israel, Oct 20 2016

Prog

(PARI) isok(n) = polisirreducible(Mod(1, 2)*(x^n + x^9 + 1)); \\ Michel Marcus, Oct 20 2016

Crossrefs

Cf. A002475.

Sequence in context: A116050 A241413 A056721 * A050140 A190860 A191214

Adjacent sequences: A057476 A057477 A057478 * A057480 A057481 A057482

Keyword

nonn

Author

Robert G. Wilson v, Sep 27 2000

Extensions

a(34)-a(41) from Robert Israel, Oct 20 2016

a(42) from Alois P. Heinz, Oct 20 2016

a(43)-a(67) from Lucas A. Brown, Nov 28 2022

Status

approved