

A049449


Product of numerator and denominator of fractions in Farey tree A007305/A007306.


2



0, 1, 2, 3, 6, 4, 10, 15, 12, 5, 14, 24, 21, 28, 40, 35, 20, 6, 18, 33, 30, 44, 65, 60, 36, 45, 84, 104, 77, 70, 88, 63, 30, 7, 22, 42, 39, 60, 90, 85, 52, 70, 133, 168, 126, 119, 152, 112, 55, 66, 144, 209, 170, 198, 273, 228, 126, 117, 204, 234, 165, 130, 154, 99, 42, 8
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OFFSET

0,3


COMMENTS

Sum of reciprocals of each row (n > 1) equals 1/2. E.g. 1/3 + 1/6, 1/4 + 1/10 + 1/15 + 1/12 and so on. The link to cuttheknot gives credit to Pierre Lamothe for this observation.  Joshua Zucker, May 11 2006


REFERENCES

J. C. Lagarias, Number Theory and Dynamical Systems, pp. 3572 of S. A. Burr, ed., The Unreasonable Effectiveness of Number Theory, Proc. Sympos. Appl. Math., 46 (1992). Amer. Math. Soc.


LINKS

Ivan Neretin, Table of n, a(n) for n = 0..4096
Alexander Bogomolny, Cuttheknot on SternBrocot trees


FORMULA

A007305*A007306.


CROSSREFS

See comment in A119272.
Sequence in context: A289272 A073318 A254047 * A104663 A246429 A305325
Adjacent sequences: A049446 A049447 A049448 * A049450 A049451 A049452


KEYWORD

nonn,easy,tabf


AUTHOR

N. J. A. Sloane.


EXTENSIONS

More terms from Megan Wawro (s1095813(AT)cedarville.edu)
More terms from Joshua Zucker, May 11 2006


STATUS

approved



