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 A091245 Number of reducible GF(2)[X]-polynomials in range [0,n]. 17
 0, 0, 0, 0, 1, 2, 3, 3, 4, 5, 6, 6, 7, 7, 8, 9, 10, 11, 12, 12, 13, 14, 15, 16, 17, 17, 18, 19, 20, 21, 22, 22, 23, 24, 25, 26, 27, 27, 28, 29, 30, 30, 31, 32, 33, 34, 35, 35, 36, 37, 38, 39, 40, 41, 42, 42, 43, 44, 45, 45, 46, 46, 47, 48, 49, 50, 51, 51, 52, 53, 54, 55, 56, 56 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,6 COMMENTS Analogous to A065855. LINKS A. Karttunen, Scheme-program for computing this sequence. EXAMPLE In range [0,8] there are the following four reducible polynomials: 4,5,6,8 thus a(8) = 4. PROG (PARI) first(n)=my(s); concat([0, 0], vector(n-1, k, s += !polisirreducible(Pol(binary(k+1))*Mod(1, 2)))) \\ Charles R Greathouse IV, Sep 02 2015 CROSSREFS Partial sums of A091247. Cf. A091242. Sequence in context: A132351 A025556 A005229 * A100618 A248227 A061288 Adjacent sequences:  A091242 A091243 A091244 * A091246 A091247 A091248 KEYWORD nonn AUTHOR Antti Karttunen, Jan 03 2004 STATUS approved

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Last modified August 10 02:28 EDT 2020. Contains 336367 sequences. (Running on oeis4.)