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Search: id:A162290
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| A162290 |
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Let A087788(n) = p*q*r, where p<q<r, be the n-th 3-Carcmichael number. Then a(n) = (p-1)*(p*q*r-1)/((q-1)*(r-1)). |
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+0
4
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| 7, 23, 48, 22, 47, 45, 45, 21, 44, 163, 162, 43, 161, 280, 1684, 1363, 159, 351, 950, 1675, 1358, 949, 158, 345, 1829, 947, 1353, 510, 938, 1660, 2796, 1820, 820, 10208, 2779, 935, 1650, 817, 937, 1822
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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A. K. Devaraj conjectured that a(n) is always an integer, and this was proved by Carl Pomerance.
a(n) may be called the Pomerance index of the n-th 3-Carmichael number.
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CROSSREFS
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Cf. A002997, A087788, A162990.
Sequence in context: A153210 A158035 A101789 this_sequence A062725 A147121 A098334
Adjacent sequences: A162287 A162288 A162289 this_sequence A162291 A162292 A162293
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KEYWORD
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nonn
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AUTHOR
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A. K. Devaraj (dkandadai(AT)yahoo.com), Jul 01 2009
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EXTENSIONS
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Edited by N. J. A. Sloane (njas(AT)research.att.com), Sep 14 2009, based on email messages from David Broadhurst and M. H. Hasler, Jul 10 2009
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