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Search: id:A141800
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| A141800 |
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For n>=2, a(n) = sum{k=1 to n} (smallest prime dividing (n*k)). a(1)=0. |
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+0
2
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OFFSET
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1,2
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EXAMPLE
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For n = 5, the smallest prime dividing 1*5=5 is 5. The smallest prime dividing 2*5=10 is 2. The smallest prime dividing 3*5=15 is 3. The smallest prime dividing 4*5=20 is 2. And the smallest prime dividing 5*5=25 is 5. So a(5) = 5+2+3+2+5 = 17.
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CROSSREFS
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Cf. A141801.
Sequence in context: A005877 A098354 A089474 this_sequence A019197 A066106 A030296
Adjacent sequences: A141797 A141798 A141799 this_sequence A141801 A141802 A141803
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KEYWORD
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more,nonn
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AUTHOR
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Leroy Quet (q1qq2qqq3qqqq(AT)yahoo.com), Jul 05 2008
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