login
This site is supported by donations to The OEIS Foundation.

 

Logo

Annual Appeal: Today, Nov 11 2014, is the 4th anniversary of the launch of the new OEIS web site. 70,000 sequences have been added in these four years, all edited by volunteers. Please make a donation (tax deductible in the US) to help keep the OEIS running.

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A176501 Farey(m; I) where m = Fibonacci (n + 1) and I = [1/n, 1]. 12
1, 2, 4, 9, 19, 50, 122, 317, 837, 2213, 5758, 15236, 40028, 105079, 276627, 727409, 1910685, 5020094 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

This sequence arises in the analytically obtained strict upper bound of the set of equivalent resistances formed by any conceivable network (series/parallel or bridge, or non-planar) of n equal resistors. Consequently it provides an strict upper bound of the sequences: A048211, A153588, A174283, A174284, A174285 and A174286. This strict upper bound provided by this difficult to compute (due to computer memory) sequence is better than the easier to compute Sequence A176499.

REFERENCES

Antoni Amengual, The intriguing properties of the equivalent resistances of n equal resistors combined in series and in parallel, American Journal of Physics, 68(2), 175-179 (February 2000). Digital Object Identifier (DOI): http://dx.doi.org/10.1119/1.19396

LINKS

Table of n, a(n) for n=1..18.

Sameen Ahmed Khan, The bounds of the set of equivalent resistances of n equal resistors combined in series and in parallel, arXiv:1004.3346v1 [physics.gen-ph], (20 April 2010).

Sameen Ahmed Khan, Mathematica notebook

EXAMPLE

n = 5, I = [1/5, 1], m = Fibonacci(5 + 1) = 8, Farey(8) = 23, Farey(8; I) = 19

CROSSREFS

A048211, A153588, A174283, A174284, A174285 and A174286, A176499, A176500, A176502.

Sequence in context: A000080 A153447 A076893 * A096354 A076838 A034749

Adjacent sequences:  A176498 A176499 A176500 * A176502 A176503 A176504

KEYWORD

more,nonn

AUTHOR

Sameen Ahmed Khan, Apr 21 2010

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

Content is available under The OEIS End-User License Agreement .

Last modified November 22 16:20 EST 2014. Contains 249807 sequences.