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A115069
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a(n) = 3^b(n), where b(n) is #{primes p=1 mod 3 dividing n}.
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1
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1, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 3, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 3, 1, 1, 1, 3, 1, 3, 3, 3, 1, 1, 3, 3, 1, 1, 1, 1, 1, 3, 1, 1, 3, 1, 1, 1, 3, 3, 1, 1, 1, 3, 3, 3, 1, 3, 1, 3, 1, 1, 3, 1, 1, 3, 3, 1, 3, 3, 3, 3, 1, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 9, 1, 3, 1, 3, 1, 3, 3, 1
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OFFSET
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1,7
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LINKS
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FORMULA
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MAPLE
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a:= n-> 3^add(`if`(irem(i[1], 3)=1, 1, 0), i=ifactors(n)[2](n)):
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MATHEMATICA
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b[n_] := Count[FactorInteger[n][[All, 1]], p_ /; Mod[p, 3] == 1];
a[1] = 1; a[n_] := 3^b[n];
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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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