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A067226
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Numbers n such that phi(5n+1) = sigma(n).
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0
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5005, 6745, 79695, 99145, 160195, 166135, 296065, 350935, 486805, 960355, 1291105, 1350745, 1817365, 2218645, 2445685, 3287680, 4069135, 5341375, 5497965, 8933085, 14495065, 15106795, 16824535, 16850995, 18510055, 18710125, 21309085, 21521500, 22453345
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Are there any terms not congruent to 5 in the sequence?
a(58) = 104447959 is the first example. [Charles R Greathouse IV, Jan 29 2012]
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PROG
| (PARI) for(n=1, 1e9, if(sigma(n)==eulerphi(5*n+1), print1(n", "))) \\ Charles R Greathouse IV, Jan 29 2012
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CROSSREFS
| Sequence in context: A035901 A108011 A018188 * A154059 A138637 A140921
Adjacent sequences: A067223 A067224 A067225 * A067227 A067228 A067229
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KEYWORD
| nonn
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AUTHOR
| Benoit Cloitre (benoit7848c(AT)orange.fr), Feb 20 2002
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EXTENSIONS
| a(11)-a(29) from Donovan Johnson (donovan.johnson(AT)yahoo.com), Jan 29 2012
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