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A119388
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Numbers n such that n == -1 (mod phi(n-1)).
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0
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2, 3, 5, 7, 11, 31, 71, 511, 2591, 131071, 3359231, 167247871, 8589934591
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OFFSET
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1,1
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COMMENTS
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This sequence has the terms from A067933 (all primes), plus 511 and 3359231 that are not primes.
Checked up to x<70000000
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LINKS
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PROG
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(PARI) for(x=1, 70000000, if(((x)+1)%eulerphi((x)-1)==0, print((x))))
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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