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 A058334 Numbers n such that the trinomial x^n + x + 1 is irreducible over GF(5). 1
 0, 1, 2, 3, 7, 18, 22, 27, 31, 78, 94, 115, 171, 402, 438, 507, 1363, 1467, 2263, 2283, 3627, 9247, 9955 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,3 COMMENTS No other n < 4400. - Michael Somos, Mar 12 2007 Next term > 10^4. [Joerg Arndt, Mar 02 2016] LINKS MATHEMATICA Do[ If[ ToString[ Factor[ x^n + x^1 + 1, Modulus -> 5] ] == ToString[ x^n + x^1 + 1], Print[n] ], {n, 0, 750} ] PROG (PARI) isok(n) = polisirreducible(Mod(1, 5)*(x^n + x + 1)); \\ Michel Marcus, Feb 11 2014 (Sage) P. = GF(5)[] for n in range(0, 10000):        if (x^n+x+1).is_irreducible():            print(n) # Joerg Arndt, Mar 02 2016 CROSSREFS Cf. A002475 (GF(2)), A058857 (GF(7)). Sequence in context: A195530 A295509 A225747 * A303090 A131093 A002864 Adjacent sequences:  A058331 A058332 A058333 * A058335 A058336 A058337 KEYWORD nonn,more,changed AUTHOR Robert G. Wilson v, Dec 13 2000 EXTENSIONS a(1) and a(2) from Eric M. Schmidt, Feb 10 2014 a(22) and a(23) from Joerg Arndt, Mar 02 2016 STATUS approved

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Last modified December 13 03:41 EST 2019. Contains 329968 sequences. (Running on oeis4.)