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Search: id:A063788
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| A063788 |
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Numbers n such that sigma(n) = 2n + Omega(n), where Omega(n) is the number of prime divisors of n (with repetition). |
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+0
1
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| 18, 88, 4030, 5830, 518656, 13174976, 134094848, 2146926592
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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a(9) <= 2251798907715584. a(10) <= 633825300114085990300727115776. a(11) <= 2596148429267411760623818083663872. [From Donovan Johnson (donovan.johnson(AT)yahoo.com), Dec 19 2008]
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PROGRAM
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(PARI) for(n=1, 10^8, if(sigma(n)==2*n+bigomega(n), print(n)))
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CROSSREFS
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Sequence in context: A124935 A126405 A141842 this_sequence A066854 A059138 A117735
Adjacent sequences: A063785 A063786 A063787 this_sequence A063789 A063790 A063791
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KEYWORD
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more,nonn
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AUTHOR
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Jason Earls (zevi_35711(AT)yahoo.com), Aug 16 2001
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EXTENSIONS
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a(7)-a(8) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Dec 19 2008
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