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 A066658 Denominators of rational numbers produced in order by A066720(j)/A066720(i) for i >= 1, 1 <= j
 1, 2, 3, 3, 5, 5, 5, 7, 7, 7, 7, 8, 4, 8, 8, 8, 11, 11, 11, 11, 11, 11, 13, 13, 13, 13, 13, 13, 13, 17, 17, 17, 17, 17, 17, 17, 17, 18, 9, 6, 18, 18, 9, 18, 18, 18, 19, 19, 19, 19, 19, 19, 19, 19, 19, 19, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 23, 29, 29 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,2 COMMENTS Does every rational number in range (0,1) appear? a(0) = 1 by convention. LINKS Reinhard Zumkeller, Table of n, a(n) for n = 0..10000 EXAMPLE Sequence of rationals begins 1, 1/2, 1/3, 2/3, 1/5, 2/5, 3/5, 1/7, 2/7, 3/7, 5/7, 1/8, 1/4, 3/8, 5/8, 7/8, 1/11, 2/11, ... PROG (Haskell) import Data.List (inits) import Data.Ratio ((%), denominator) a066658 n = a066658_list !! n a066658_list = map denominator    (1 : (concat \$ tail \$ zipWith (\u vs -> map (% u) vs)                                  a066720_list (inits a066720_list))) -- Reinhard Zumkeller, Nov 19 2013 CROSSREFS Cf. A066657 (numerators), A066720. Sequence in context: A130149 A053046 A261179 * A005145 A280740 A156350 Adjacent sequences:  A066655 A066656 A066657 * A066659 A066660 A066661 KEYWORD nonn,frac,nice AUTHOR N. J. A. Sloane, Jan 18 2002 STATUS approved

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Last modified April 12 09:59 EDT 2021. Contains 342920 sequences. (Running on oeis4.)