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A247765 Table of denominators in the Egyptian fraction representation of n/(n+1) by the greedy algorithm. 3
2, 2, 6, 2, 4, 2, 4, 20, 2, 3, 2, 3, 42, 2, 3, 24, 2, 3, 18, 2, 3, 15, 2, 3, 14, 231, 2, 3, 12, 2, 3, 12, 156, 2, 3, 11, 231, 2, 3, 10, 2, 3, 10, 240, 2, 3, 10, 128, 32640, 2, 3, 9, 2, 3, 9, 342, 2, 3, 9, 180, 2, 3, 9, 126, 2, 3, 9, 99, 2, 3, 9, 83, 34362 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A100678(n) = length of n-th row;

T(n, A100678(n)) = A100695(n).

LINKS

Reinhard Zumkeller, Rows n = 1..100 of triangle, flattened

EXAMPLE

.   1:  2

.   2:  2, 6

.   3:  2, 4

.   4:  2, 4, 20

.   5:  2, 3

.   6:  2, 3, 42

.   7:  2, 3, 24

.   8:  2, 3, 18

.   9:  2, 3, 15

.  10:  2, 3, 14, 231

.  11:  2, 3, 12

.  12:  2, 3, 12, 156

.  13:  2, 3, 11, 231

.  14:  2, 3, 10

.  15:  2, 3, 10, 240

.  16:  2, 3, 10, 128, 32640

.  17:  2, 3,  9

.  18:  2, 3,  9, 342

.  19:  2, 3,  9, 180

.  20:  2, 3,  9, 126

PROG

(Haskell)

import Data.Ratio ((%), numerator, denominator)

a247765 n k = a247765_tabf !! (n-1) !! (k-1)

a247765_tabf = map a247765_row [1..]

a247765_row n = f (map recip [2..]) (n % (n + 1)) where

   f es x | numerator x == 1 = [denominator x]

          | otherwise        = g es

          where g (u:us) | u <= x    = (denominator u) : f us (x - u)

                         | otherwise =  g us

CROSSREFS

Cf. A100678, A100695.

Sequence in context: A205506 A110141 A293443 * A129750 A278234 A068976

Adjacent sequences:  A247762 A247763 A247764 * A247766 A247767 A247768

KEYWORD

nonn,tabf

AUTHOR

Reinhard Zumkeller, Sep 25 2014

STATUS

approved

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Last modified April 22 14:52 EDT 2019. Contains 322356 sequences. (Running on oeis4.)