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A087077
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Total number of elements in all primitive subsets of the integers 1 to n.
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2
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0, 1, 2, 5, 8, 21, 29, 73, 105, 193, 288, 677, 853, 1957, 2961, 4913, 6809, 15145, 19605, 43105, 57889, 98849, 151457, 327505, 397825, 784945, 1201189, 2009229, 2772729, 5901185, 7364945, 15609825, 21206049, 36440033
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| A primitive set has no element that divides another element in the same set.
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REFERENCES
| R. K. Guy, Unsolved Problems in Number Theory, Springer-Verlag, New York, (1994).
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LINKS
| Eric Weisstein's World of Mathematics, Primitive Sequence.
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EXAMPLE
| a(4)=8 since the primitive subsets of (1,2,3,4) are ( ) (1) (2) (3) (4) (2,3) (3,4) and these contain eight elements
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CROSSREFS
| A051026 gives the number of primitive subsets. A087078 gives the sum of the elements of the primitive subsets. A087080 gives the number elements in the coprime subsets
Sequence in context: A107384 A205596 A092446 * A200276 A168081 A117647
Adjacent sequences: A087074 A087075 A087076 * A087078 A087079 A087080
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KEYWORD
| more,nonn
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AUTHOR
| Alan Sutcliffe (alansut(AT)ntlworld.com), Aug 10 2003
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