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A068402
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Numbers n such that sigma(n+1)=n+phi(n).
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0
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4, 6, 32, 38, 54, 56, 84, 278, 2664, 10944, 15608, 20720, 84800, 179576, 209664, 6251904
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Are there any odd values in the sequence?
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PROG
| (PARI) : for(n=1, 500000, if(sigma(n+1)-n==eulerphi(n), print1(n, ", ")))
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CROSSREFS
| Sequence in context: A088255 A192083 A068720 * A078250 A087299 A164127
Adjacent sequences: A068399 A068400 A068401 * A068403 A068404 A068405
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KEYWORD
| easy,nonn
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AUTHOR
| Benoit Cloitre (benoit7848c(AT)orange.fr), Mar 02 2002
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EXTENSIONS
| One more term from Rick L. Shepherd (rshepherd2(AT)hotmail.com), Jun 21 2002
Any additional terms are greater than 20000000.
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