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A104658
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Number of distinct prime factors of 23 concatenated n times.
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1
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1, 2, 5, 4, 4, 7, 4, 6, 8, 7, 6, 10, 6, 8, 13, 11, 6, 11, 3, 11, 14, 10, 6, 13, 10, 9, 12, 12, 8, 20, 5, 15, 14, 10, 12, 17, 7, 6, 15, 15
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OFFSET
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1,2
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LINKS
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FORMULA
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EXAMPLE
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Number of distinct prime factors of 23 is 1 (prime).
Number of distinct prime factors of 2323 is 2.
Number of distinct prime factors of 232323 is 5.
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MAPLE
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A104658 := proc(n) local x ; x := 23 ; for j from 2 to n do x := 100*x+23 ; end do; numtheory[factorset](%) ; nops(%) ; end proc: # R. J. Mathar, Aug 24 2011
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MATHEMATICA
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Table[PrimeNu[FromDigits[PadRight[{}, 2n, {2, 3}]]], {n, 40}] (* or *) PrimeNu[NestList[100#+23&, 23, 40]] (* Harvey P. Dale, May 21 2012 *)
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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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