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A066657 Numerators of rational numbers produced in order by A066720(j)/A066720(i) for i >= 1, 1 <= j <i. 8
1, 1, 1, 2, 1, 2, 3, 1, 2, 3, 5, 1, 1, 3, 5, 7, 1, 2, 3, 5, 7, 8, 1, 2, 3, 5, 7, 8, 11, 1, 2, 3, 5, 7, 8, 11, 13, 1, 1, 1, 5, 7, 4, 11, 13, 17, 1, 2, 3, 5, 7, 8, 11, 13, 17, 18, 1, 2, 3, 5, 7, 8, 11, 13, 17, 18, 19, 1, 2, 3, 5, 7, 8, 11, 13, 17, 18, 19, 23, 1, 2, 3, 5, 7 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,4

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 ((%), numerator)

a066657 n = a066657_list !! n

a066657_list = map numerator

   (1 : (concat $ tail $ zipWith (\u vs -> map (% u) vs)

                                 a066720_list (inits a066720_list)))

-- Reinhard Zumkeller, Nov 19 2013

CROSSREFS

Cf. A066658 (denominators), A066720.

Sequence in context: A162192 A238954 A238967 * A119444 A060040 A092080

Adjacent sequences:  A066654 A066655 A066656 * A066658 A066659 A066660

KEYWORD

nonn,frac,nice

AUTHOR

N. J. A. Sloane, Jan 18 2002

STATUS

approved

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Last modified May 27 06:24 EDT 2019. Contains 323599 sequences. (Running on oeis4.)