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A057476 Numbers n such that x^n + x^6 + 1 is irreducible over GF(2). 2
1, 3, 5, 7, 17, 31, 71, 97, 167, 175, 209, 385, 2159, 5617, 8921 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

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

LINKS

Table of n, a(n) for n=1..15.

MAPLE

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

MATHEMATICA

Do[ If[ ToString[ Factor[ x^n + x^6 + 1, Modulus -> 2 ] ] == ToString[ x^n + x^6 + 1 ], Print[ n ] ], {n, 0, 750} ]

CROSSREFS

Cf. A002475.

Sequence in context: A274906 A296422 A174394 * A016041 A140797 A245730

Adjacent sequences:  A057473 A057474 A057475 * A057477 A057478 A057479

KEYWORD

nonn

AUTHOR

Robert G. Wilson v, Sep 27 2000

EXTENSIONS

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

STATUS

approved

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Last modified February 20 15:20 EST 2019. Contains 320336 sequences. (Running on oeis4.)