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Search: id:A070222
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| A070222 |
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Numbers n such that the sum of prime divisors of n divides the sum of divisors of n. |
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+0
1
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| 15, 20, 24, 35, 42, 54, 66, 72, 95, 98, 100, 104, 108, 110, 114, 119, 120, 126, 132, 135, 140, 143, 160, 168, 189, 195, 207, 209, 216, 220, 224, 258, 264, 270, 276, 287, 290, 294, 319, 322, 323, 351, 360, 363, 375, 377, 378, 384, 392, 432, 440, 456, 459, 464
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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The sum of divisors of 132 is sigma(132)=336; prime divisors of 132 are 2,3,11 and (336)/(2+3+11)=336/16=21 hence 132 is in the sequence.
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PROGRAM
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(PARI) for(n=2, 700, if(sigma(n)%sumdiv(n, d, isprime(d)*d)==0, print1(n, ", ")))
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CROSSREFS
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Sequence in context: A102495 A133288 A014603 this_sequence A143321 A066860 A120159
Adjacent sequences: A070219 A070220 A070221 this_sequence A070223 A070224 A070225
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KEYWORD
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easy,nonn
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AUTHOR
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Benoit Cloitre (benoit7848c(AT)orange.fr), May 07 2002
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