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A070287
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Numbers n such that the equation lcm(sigma(x),phi(x))=n has solutions.
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0
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1, 3, 4, 12, 14, 24, 28, 36, 48, 60, 72, 78, 84, 96, 120, 144, 168, 180, 192, 240, 248, 264, 288, 312, 336, 360, 420, 432, 480, 496, 576, 620, 672, 684, 720, 780, 792, 798, 840, 864, 924, 936, 960, 1008, 1056, 1080, 1092, 1104, 1176, 1240, 1260, 1344, 1368
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OFFSET
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1,2
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LINKS
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PROG
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(PARI) for(n=1, 2000, if(0<sum(i=1, n, if(lcm(sigma(i), eulerphi(i))-n, 0, 1)), print1(n, ", ")))
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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STATUS
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approved
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