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 A081664 For the smallest q for which there exists a fraction p/q containing n in its decimal expansion, this sequence gives the smallest p. 1
 1, 1, 1, 2, 1, 2, 3, 4, 9, 1, 1, 1, 2, 1, 2, 1, 1, 2, 1, 1, 3, 2, 1, 6, 1, 4, 3, 1, 1, 3, 5, 8, 1, 1, 5, 4, 3, 2, 1, 2, 5, 1, 7, 4, 5, 2, 1, 12, 1, 1, 5, 1, 2, 5, 5, 9, 1, 7, 13, 3, 2, 5, 4, 9, 13, 2, 19, 11, 1, 7, 1, 3, 11, 2, 3, 1, 7, 11, 19, 4, 2, 1, 5, 2, 1, 13, 7, 8, 1, 9, 11, 1, 14, 1, 19, 24, 33, 49 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS Inspired by problem 14 on the 2003 American Invitational Mathematics Examination, which asked for a(251). There are some slightly different versions of this sequence. For example, you could consider 1/2 = .5 or 1/2 = .50000...; I chose the latter interpretation here. LINKS American Mathematics Competitions, Problem 14 EXAMPLE a(6) = 2 because 2/3 = .6...; a(24) = 6 because 6/25 = .24 CROSSREFS A081665 gives the denominators. Sequence in context: A325841 A076480 A002730 * A224926 A117673 A107946 Adjacent sequences:  A081661 A081662 A081663 * A081665 A081666 A081667 KEYWORD base,frac,nonn AUTHOR Joshua Zucker, Mar 26 2003 STATUS approved

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Last modified January 27 04:57 EST 2020. Contains 331291 sequences. (Running on oeis4.)