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Search: id:A067890
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| A067890 |
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Primes p such that phi(p+1)=phi(p-1). |
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+0
1
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| 5, 11, 71, 911, 1609, 2591, 4339, 15401, 58309, 59149, 80989, 208391, 215389, 496511, 589189, 1809079, 1970149, 3167569, 3260809, 3516109, 5914369, 9832271, 12231311, 13608071, 14470061, 16537151, 16692551, 19018369, 19462661
(list; graph; listen)
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OFFSET
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1,1
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PROGRAM
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(PARI) v=[]; forprime(p=2, 40000000, if(eulerphi(p+1)==eulerphi(p-1), v=concat(v, p))); v
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CROSSREFS
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Sequence in context: A101209 A050568 A065555 this_sequence A002359 A090518 A057726
Adjacent sequences: A067887 A067888 A067889 this_sequence A067891 A067892 A067893
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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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EXTENSIONS
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More terms from Rick L. Shepherd (rshepherd2(AT)hotmail.com), May 03 2002
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