OFFSET
1,2
LINKS
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).
Sameen Ahmed Khan, Mathematica notebook for A153588 and A058351
Sameen Ahmed Khan, The bounds of the set of equivalent resistances of n equal resistors combined in series and in parallel, arXiv:1004.3346 [physics.gen-ph], 2010.
Sameen Ahmed Khan, How Many Equivalent Resistances?, RESONANCE, May 2012.
Sameen Ahmed Khan, Beginning to count the number of equivalent resistances, Indian Journal of Science and Technology, 2016, Vol 9(44).
M. Ortolano, M. Abrate, and L. Callegaro, On the synthesis of Quantum Hall Array Resistance Standards, arXiv preprint arXiv:1311.0756 [physics.ins-det], 2013.
Project Euler, Problem 155: Counting Capacitor Circuits.
EXAMPLE
For n=2 there are 3 solutions, 1 ohm, (1+1) ohms and 1/(1/1+1/1)=1/2 ohm. So a(2)=3.
CROSSREFS
Cf. A048211. This sequence is the total number of resistance values formed using up to n resistances, A048211 is the total number of resistance values formed using exactly n resistances.
KEYWORD
hard,more,nonn
AUTHOR
Altrego Janeway (altrego99(AT)gmail.com), Dec 29 2008
EXTENSIONS
a(17)-a(25) from Antoine Mathys, Apr 02 2015
Definition clarified by Antoine Mathys, Apr 03 2015
a(26)-a(30) from Antoine Mathys, Dec 08 2024
STATUS
approved