A057476 Numbers k such that x^k + x^6 + 1 is irreducible over GF(2).

1, 3, 5, 7, 17, 31, 71, 97, 167, 175, 209, 385, 2159, 5617, 8921, 33425, 39119, 76625, 110249, 192127, 255265

Offset

1,2

Comments

a(16) > 30000 if it exists. - Robert Israel, Nov 11 2016

Any subsequent terms are > 300000. - Lucas A. Brown, Nov 28 2022

Links

Table of n, a(n) for n=1..21.

Lucas A. Brown, Python program.

Lucas A. Brown, Sage program.

Maple

select(n -> Irreduc(x^n+x^6+1) mod 2, [$1..1000]); # Robert Israel, Nov 11 2016

Crossrefs

Cf. A002475.

Sequence in context: A296422 A370686 A174394 * A016041 A140797 A245730

Adjacent sequences: A057473 A057474 A057475 * A057477 A057478 A057479

Keyword

nonn,more

Author

Robert G. Wilson v, Sep 27 2000

Extensions

a(13)-a(15) from Robert Israel, Nov 11 2016

a(16)-a(21) from Lucas A. Brown, Nov 28 2022

Status

approved