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Search: id:A068400
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| A068400 |
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Numbers n such that sigma(n)=phi(n*bigomega(n)). |
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+0
1
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| 248, 357, 1045, 3596, 3956, 4064, 5396, 8636, 20026, 20320, 23374, 24871, 25714, 29029, 33915, 35074, 39585, 41656, 50065, 55154, 56134, 56536, 58435, 61344, 64285, 74613, 79000, 87087, 87685, 137885, 140335, 142240
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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Comment from Giovanni Resta, Nov 15 2006: For all the numbers listed, gcd(n!-1,2^n+1) = 2n+1. Is this always true? Reply from Max Alekseyev, Nov 16 2006: This is plausible and true for n up to 45000.
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CROSSREFS
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Sequence in context: A048901 A065146 A064977 this_sequence A109478 A033554 A109476
Adjacent sequences: A068397 A068398 A068399 this_sequence A068401 A068402 A068403
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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), Mar 02 2002
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