# Plotting a family of contour plots [duplicate]

How can I plot the following equation with $k$ assumed to be an integer"? I tried something like this, but it doesn't work:

ContourPlot[{Element[k,Integers], Sqrt[x^2 + y^2] == 4 + k*Pi},{x, -17, 17}, {y, -17, 17}]

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Possible duplicate: mathematica.stackexchange.com/q/3871/5 –  rm -rf May 25 at 21:36

## migrated from math.stackexchange.comMay 25 at 21:26

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## marked as duplicate by Sjoerd C. de Vries, Jens, m_goldberg, rm -rf♦May 26 at 5:28

This sounds like what you want:

ContourPlot[Sqrt[x^2 + y^2], {x, -17, 17}, {y, -17, 17},
Contours -> Table[4 + k*Pi, {k, -10, 10}]]


which produces

or perhaps you want the image to be styled like this

which is obtained by adding the option ContourShading -> None.

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Don't working.... –  Lior May 25 at 17:34
Can you be more specific... what isn't working. Is this not the sort of picture you want? Does your copy of Mathematica not recognize these commands? –  Zev Chonoles May 25 at 17:36
not, there's not output. and these is the free trial. –  Lior May 25 at 17:38
Or alternately: ContourPlot[ Evaluate@Table[Sqrt[x^2 + y^2] == 4 + k*Pi, {k, -10, 10}], {x, -17, 17}, {y, -17, 17}] –  rm -rf May 25 at 21:32
Doesn't working... –  Lior May 27 at 14:42