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A074374
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s(s+1)/2 where s is the sum of the prime factors of n (with repetition).
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4
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0, 0, 3, 6, 10, 15, 15, 28, 21, 21, 28, 66, 28, 91, 45, 36, 36, 153, 36, 190, 45, 55, 91, 276, 45, 55, 120, 45, 66, 435, 55, 496, 55, 105, 190, 78, 55, 703, 231, 136, 66, 861, 78, 946, 120, 66, 325, 1128, 66, 105, 78, 210, 153, 1431, 66, 136, 91, 253, 496, 1770, 78
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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LINKS
| Neville Holmes, Integer Sequence Combinations
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EXAMPLE
| a(10)=7(7+1)/2=28 because 7 is the sum of the prime factors of 10.
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MATHEMATICA
| f[n_]:=Module[{c=Total[Times@@@FactorInteger[n]]}, (c(c+1))/2]; Join[{0, 0}, Array[f, 60, 2]] (* From Harvey P. Dale, Aug 21 2011 *)
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PROG
| (PARI) s(n)=sum(i=1, omega(n), component(component(factor(n), 1), i)*component(component(factor(n), 2), i))); a(n)=s(n)*(s(n)+1)/2
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CROSSREFS
| A000217 applied to A001414. Cf. A074372.
Sequence in context: A105333 A126234 A130484 * A109804 A120993 A194458
Adjacent sequences: A074371 A074372 A074373 * A074375 A074376 A074377
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KEYWORD
| easy,nonn
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AUTHOR
| Neville Holmes (neville.holmes(AT)utas.edu.au), Aug 29 2002
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EXTENSIONS
| More terms from Benoit Cloitre (benoit7848c(AT)orange.fr), Sep 02 2002
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