

A178031


Consider the Farey tree A006842/A006843; a(n) = row at which the denominator n first appears (assumes first row is labeled row 1).


3



1, 2, 3, 4, 4, 6, 5, 5, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 8, 7, 8, 8, 8, 8, 8, 8, 9, 8, 8, 8, 9, 9, 8, 9, 9, 9, 10, 9, 9, 9, 10, 9, 9, 9, 9, 9, 10, 9, 9, 10, 10, 10, 11, 9, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10
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OFFSET

1,2


COMMENTS

Computed by Alan Wechsler, Dec 16, 2010.
Richard C. Schroeppel also asked about the analogous sequence giving the last occurrence of denominator n.


REFERENCES

Based on a posting by Richard C. Schroeppel to the Math Fun Mailing List, Dec 15 2010.


LINKS

Bo Gyu Jeong, Table of n, a(n) for n = 1..10000
Richard J. Mathar, The Kepler binary tree of reduced fractions, 2017.


CROSSREFS

See A178047 for another version. Cf. A006842, A006843, A177903, A178042.
Sequence in context: A180046 A008329 A064558 * A008328 A298933 A091860
Adjacent sequences: A178028 A178029 A178030 * A178032 A178033 A178034


KEYWORD

nonn


AUTHOR

N. J. A. Sloane, Dec 16 2010


EXTENSIONS

More terms from Bo Gyu Jeong, Oct 20 2012


STATUS

approved



