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A167295
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Totally multiplicative sequence with a(p) = 3*(p-2) for prime p.
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1
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1, 0, 3, 0, 9, 0, 15, 0, 9, 0, 27, 0, 33, 0, 27, 0, 45, 0, 51, 0, 45, 0, 63, 0, 81, 0, 27, 0, 81, 0, 87, 0, 81, 0, 135, 0, 105, 0, 99, 0, 117, 0, 123, 0, 81, 0, 135, 0, 225, 0, 135, 0, 153, 0, 243, 0, 153, 0, 171, 0, 177, 0, 135, 0, 297, 0, 195, 0, 189, 0, 207
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OFFSET
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1,3
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LINKS
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FORMULA
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Multiplicative with a(p^e) = (3*(p-2))^e. If n = Product p(k)^e(k) then a(n) = Product (3*(p(k)-2))^e(k).
a(2k) = 0 for k >= 1.
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MATHEMATICA
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a[1] = 1; a[n_] := (fi = FactorInteger[n]; Times @@ ((fi[[All, 1]] - 2)^fi[[All, 2]])); Table[a[n]*3^PrimeOmega[n], {n, 1, 100}](* G. C. Greubel, Jun 05 2016 *)
f[p_, e_] := (3*(p-2))^e; a[1] = 1; a[n_] := Times @@ f @@@ FactorInteger[n]; Array[a, 100] (* Amiram Eldar, Oct 19 2023 *)
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CROSSREFS
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KEYWORD
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nonn,easy,mult
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AUTHOR
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STATUS
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approved
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