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Search: id:A038626
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| A038626 |
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Smallest value of pi(x) having n*pi(x) = x. |
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+0
5
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| 1, 9, 24, 66, 168, 437, 1051, 2614, 6454, 15927, 40071, 100346, 251706, 637197, 1617172, 4124436, 10553399, 27066969, 69709679, 179992838, 465769802, 1208198523, 3140421715
(list; graph; listen)
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OFFSET
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2,2
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COMMENT
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Golomb shows that solutions exist for each n>1.
a(n) is the smallest natural number m such that m = pi(n*m). For all known terms of this sequence the relation, " 2.4*a(n) < a(n+1) < 2.7*a(n) + 7 " is true. A038627(n) gives number of natural solutions of the equation m = pi(n*m). - Farideh Firoozbakht (mymontain(AT)yahoo.com), Jan 09 2005
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REFERENCES
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S. W. Golomb, On the Ratio of N to pi(N), American Mathematical Monthly, 69 (1962), 36-37.
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LINKS
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Eric Weisstein's World of Mathematics, Link to a section of The World of Mathematics.
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EXAMPLE
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pi(3059) = 437 and 3059/437 = 7, so a(7)=437
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CROSSREFS
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Cf. A038623-A038627, A102281, A087237.
Sequence in context: A022787 A079770 A079771 this_sequence A121089 A050282 A096757
Adjacent sequences: A038623 A038624 A038625 this_sequence A038627 A038628 A038629
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KEYWORD
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nonn
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AUTHOR
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Jud McCranie (j.mccranie(AT)comcast.net)
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EXTENSIONS
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One more term from Farideh Firoozbakht (mymontain(AT)yahoo.com), Jan 09 2005
Edited by N. J. A. Sloane (njas(AT)research.att.com) at the suggestion of Chris Caldwell, Apr 08 2008
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