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A066658 Denominators of rational numbers produced in order by A066720(j)/A066720(i) for i >= 1, 1 <= j <i. 8
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: A083662 A130149 A053046 * A005145 A156350 A076367

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 November 23 16:13 EST 2014. Contains 249851 sequences.