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A058823
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a(0) = 1, a(1) = 8; for n >= 2 a(n) is the number of degree-n monic reducible polynomials over GF(8), i.e., a(n) = 8^n - A027380(n).
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0
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1, 8, 36, 344, 3088, 26216, 218548, 1797560, 14680576, 119304704, 966370924, 7809031448, 62992875856, 507466905128, 4083900481540, 32838747285128, 263882791714816, 2119341001115528, 17013598599759616, 136530178177126616, 1095275429430191920, 8784163844623695896
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OFFSET
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0,2
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COMMENTS
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Dimensions of homogeneous subspaces of shuffle algebra over 8-letter alphabet (see A058766 for 2-letter case).
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REFERENCES
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M. Lothaire, Combinatorics on words, Cambridge mathematical library, 1983, p. 126 (definition of shuffle algebra).
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LINKS
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MATHEMATICA
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a[n_] := 8^n - DivisorSum[n, MoebiusMu[n/#] * 8^# &] / n; a[0] = 1; a[1] = 8; Array[a, 22, 0] (* Amiram Eldar, Aug 13 2023 *)
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PROG
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(PARI) a(n) = if (n<=1, 8^n, 8^n - sumdiv(n, d, moebius(d)*8^(n/d))/n); \\ Michel Marcus, Oct 30 2017
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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Claude Lenormand (claude.lenormand(AT)free.fr), Jan 04 2001
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EXTENSIONS
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Better description from Sharon Sela (sharonsela(AT)hotmail.com), Feb 19 2002
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STATUS
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approved
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