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A271607
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Number of set partitions of [2n+1] such that n+1 is the largest element of the last block.
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2
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1, 1, 6, 63, 1039, 24190, 745107, 29058813, 1389893708, 79588371929, 5353760622719, 416660175523064, 37047640989016445, 3724084616168887373, 419437505978046355690, 52523298180976612585435, 7263669823685446959438851, 1102849583101324096499809166
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OFFSET
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0,3
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COMMENTS
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Each set partition is written as a sequence of blocks, ordered by the smallest elements in the blocks.
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LINKS
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FORMULA
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EXAMPLE
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a(0) = 1: 1.
a(1) = 1: 13|2.
a(2) = 6: 1245|3, 145|23, 145|2|3, 14|25|3, 15|24|3, 1|245|3.
a(3) = 63: 123567|4, 12567|34, 12567|3|4, 1256|37|4, ..., 1|26|357|4, 17|2|356|4, 1|27|356|4, 1|2|3567|4.
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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