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Search: id:A053732
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| A053732 |
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Number of ways to partition {1,...,n} into arithmetic progressions of length >= 1. |
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+0
2
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| 1, 2, 5, 13, 37, 111, 359, 1211, 4338, 16205, 63305, 254803, 1073370, 4638359, 20731961, 95072041, 449599410, 2170162939, 10782813595, 54579794359, 283240154578
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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a(4) gives the total number of partitions of {1,2,3,4} (Bell(4); see A000110) excluding the partitions {1,2,4}{3} and {1,3,4}{2}. Hence a(4) = 15 - 2 = 13.
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CROSSREFS
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Cf. A000110.
Sequence in context: A003080 A149854 A151442 this_sequence A119495 A148301 A149855
Adjacent sequences: A053729 A053730 A053731 this_sequence A053733 A053734 A053735
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KEYWORD
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more,nonn,nice
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AUTHOR
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Marty Getz and Dixon Jones (ffmpg1(AT)uaf.edu, fndjj(AT)uaf.edu), Feb 13 2000
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EXTENSIONS
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More terms from Winston C. Yang (winston(AT)cs.wisc.edu), May 20 2001
a(15)-a(21) from Giovanni Resta (g.resta(AT)iit.cnr.it), Feb 23 2009
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