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Search: id:A077646
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| A077646 |
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Solutions to LCM[x,tau[x]]=2x which are neither primes(p), nor even-primes [2p]. |
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1
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| 45, 63, 75, 90, 99, 117, 120, 126, 147, 150, 153, 168, 171, 198, 207, 216, 234, 243, 261, 264, 279, 280, 294, 306, 312, 333, 342, 363, 369, 387, 405, 408, 414, 420, 423, 440, 456, 477, 486, 507, 520, 522, 531, 540, 549, 552, 558, 603, 616, 639, 657, 660
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OFFSET
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1,1
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FORMULA
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Composite solutions to A009530[x]=2x which are not twice a prime.
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EXAMPLE
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x=63, d[x]=tau[x]=3.2=6, LCM[63,6]=126=2x; If it was x=p(odd) or y=2p, then LCM[x,d[x]]=LCM[p,2]=2p or LCN[2p,4]=2p.
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CROSSREFS
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Cf. A009530, A001747, A000040, A065091.
Sequence in context: A138046 A140276 A140277 this_sequence A046364 A051773 A140278
Adjacent sequences: A077643 A077644 A077645 this_sequence A077647 A077648 A077649
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KEYWORD
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nonn
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AUTHOR
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Labos E. (labos(AT)ana.sote.hu), Nov 18 2002
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