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A090637
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Trajectory of 28 under the map k -> A003415(k) (taking the arithmetic derivative).
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3
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28, 32, 80, 176, 368, 752, 1520, 3424, 8592, 20096, 70464, 235072, 705280, 3023616, 13223680, 55540736, 278539264, 1392697344, 9541095424, 58609614848, 410267320320, 3397142953984, 24143851798528, 176071227916288, 1232666139967488, 9523075842834432
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OFFSET
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1,1
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COMMENTS
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LINKS
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EXAMPLE
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a(2) = 28' = (2^2*7)' = 28*(2/2 + 1/7) = 32.
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MAPLE
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a:= proc(n) option remember; `if`(n=1, 28, (t->
t*add(i[2]/i[1], i=ifactors(t)[2]))(a(n-1)))
end:
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PROG
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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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