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A135462
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a(n) = number of Eisenstein primes (see A055664) of norm <= n.
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4
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0, 0, 0, 6, 12, 12, 12, 24, 24, 24, 24, 24, 24, 36, 36, 36, 36, 36, 36, 48, 48, 48, 48, 48, 48, 54, 54, 54, 54, 54, 54, 66, 66, 66, 66, 66, 66, 78, 78, 78, 78, 78, 78, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 90, 102, 102, 102, 102, 102
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OFFSET
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0,4
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REFERENCES
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L. W. Reid, The Elements of the Theory of Algebraic Numbers, MacMillan, NY, 1910, see Chap. VI.
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LINKS
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FORMULA
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MATHEMATICA
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A055667[n_] := Which[n == 3, 6, PrimeQ[n] && Mod[n, 6] == 1, 12, PrimeQ[p = Sqrt[n]] && Mod[p, 3] == 2, 6, True, 0]; Accumulate[Array[A055667, 66, 0]] (* Jean-François Alcover, Feb 28 2018 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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