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A088865
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(Sum of distinct prime factors)^(sum of prime exponents).
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5
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1, 2, 3, 4, 5, 25, 7, 8, 9, 49, 11, 125, 13, 81, 64, 16, 17, 125, 19, 343, 100, 169, 23, 625, 25, 225, 27, 729, 29, 1000, 31, 32, 196, 361, 144, 625, 37, 441, 256, 2401, 41, 1728, 43, 2197, 512, 625, 47, 3125, 49, 343, 400, 3375, 53, 625, 256, 6561, 484, 961
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OFFSET
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1,2
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COMMENTS
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a(n) = n iff n is 1 or a prime power; otherwise, a(n) > n. - Ivan Neretin, May 31 2016
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LINKS
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FORMULA
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EXAMPLE
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a(75) = a(3^1 * 5^2) = (3+5)^(1+2) = 8^3 = 512.
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MATHEMATICA
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pf2pe[n_]:=Module[{tfi=Transpose[FactorInteger[n]]}, Total[ First[tfi]]^ Total[ Last[tfi]]]; Array[pf2pe, 60] (* Harvey P. Dale, Sep 21 2011 *)
Array[Power @@ Map[Total, Transpose@ FactorInteger@ #] &, 58] (* Michael De Vlieger, Apr 25 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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STATUS
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approved
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