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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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1
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1, 1, 2, 5, 13, 37, 111, 359, 1211, 4338, 16205, 63305, 254803, 1073370, 4638359, 20731961, 95072041, 449599410, 2170162939, 10782813595, 54579794359, 283240154578, 1497311544427, 8092773946020, 44438105067443, 249435020112771, 1420933555310524, 8249315265492112, 48599942367553271
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OFFSET
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0,3
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LINKS
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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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KEYWORD
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nonn,nice
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AUTHOR
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Marty Getz (ffmpg1(AT)uaf.edu) and Dixon Jones (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(0) prepended and a(22)-a(28) added by Max Alekseyev, Feb 11 2024
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STATUS
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approved
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