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A023023
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Number of partitions of n into 3 unordered relatively prime parts.
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2
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1, 1, 2, 2, 4, 4, 6, 6, 10, 8, 14, 12, 16, 16, 24, 18, 30, 24, 32, 30, 44, 32, 50, 42, 54, 48, 70, 48, 80, 64, 80, 72, 96, 72, 114, 90, 112, 96, 140, 96, 154, 120, 144, 132, 184, 128, 196, 150, 192, 168, 234, 162, 240, 192, 240, 210, 290, 192, 310, 240, 288, 256, 336, 240, 374
(list; graph; refs; listen; history; internal format)
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OFFSET
| 3,3
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LINKS
| Mohamed El Bachraoui, Partitions with relatively prime parts [From Jonathan Sondow (jsondow(AT)alumni.princeton.edu), May 27 2009]
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FORMULA
| G.f. for the number of partitions of n into m unordered relatively prime parts is Sum(moebius(k)*x^(m*k)/Product(1-x^(i*k), i=1..m), k=1..infinity). - Vladeta Jovovic (vladeta(AT)eunet.rs), Dec 21 2004
a(n) = (n^2/12)*Product_{prime p|n} (1 - 1/p^2) for n > 3 (proved by Mohamed El Bachraoui). [From Jonathan Sondow (jsondow(AT)alumni.princeton.edu), May 27 2009]
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CROSSREFS
| Cf. A023022-A023030, A000741-A000743, A023031-A023035, A101271.
Sequence in context: A001362 A001310 A029009 * A184157 A008643 A008644
Adjacent sequences: A023020 A023021 A023022 * A023024 A023025 A023026
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KEYWORD
| nonn
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AUTHOR
| David W. Wilson (davidwwilson(AT)comcast.net)
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