

A153588


Number of resistance values that can be constructed using up to n equal resistances by arranging them in an arbitrary seriesparallel arrangement.


17



1, 3, 7, 15, 35, 77, 179, 429, 1039, 2525, 6235, 15463, 38513, 96231, 241519, 607339, 1529533, 3857447, 9743247, 24634043, 62335495, 157885967, 400211085, 1015080877, 2576308943
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OFFSET

1,2


LINKS



EXAMPLE

Example: For n=2 there are 3 solutions, 1 ohm, (1+1) ohms and 1/(1/1+1/1)=1/2 ohm.


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.
Cf. A048211, A153588, A174283, A174284, A174285 and A174286, A176497, A176498, A176499, A176500, A176501, A176502. [Sameen Ahmed Khan, Apr 27 2010]


KEYWORD

hard,more,nonn


AUTHOR

Altrego Janeway (altrego99(AT)gmail.com), Dec 29 2008


EXTENSIONS



STATUS

approved



