English: A Bird in Flight by mathematical artist Hamid Naderi Yeganeh. This image shows all circles of the form: ${\displaystyle (x-A(k))^{2}+(y-B(k))^{2}=(R(k))^{2}}$, for ${\displaystyle k=-10000,-9999,...,9999,10000}$, where

${\displaystyle A(k)=\left({\frac {3k}{20000}}\right)+\sin \left(\left({\frac {\pi }{2}}\right)\left({\frac {k}{10000}}\right)^{7}\right)\left(\cos \left({\frac {41\pi k}{10000}}\right)\right)^{6}+\left({\frac {1}{4}}\right)\left(\cos \left({\frac {41\pi k}{10000}}\right)\right)^{16}\left(\cos \left({\frac {\pi k}{20000}}\right)\right)^{12}\sin \left({\frac {6\pi k}{10000}}\right),}$

${\displaystyle B(k)=-\cos \left(\left({\frac {\pi }{2}}\right)\left({\frac {k}{10000}}\right)^{7}\right)\left(1+\left({\frac {3}{2}}\right)\left(\cos \left({\frac {\pi k}{20000}}\right)\cos \left({\frac {3\pi k}{20000}}\right)\right)^{6}\right)\left(\cos \left({\frac {41\pi k}{10000}}\right)\right)^{6}+\left({\frac {1}{2}}\right)\left(\cos \left({\frac {3\pi k}{100000}}\right)\cos \left({\frac {9\pi k}{100000}}\right)\cos \left({\frac {18\pi k}{100000}}\right)\right)^{10},}$

${\displaystyle R(k)=\left({\frac {1}{50}}\right)+\left({\frac {1}{10}}\right)\left(\sin \left({\frac {41\pi k}{10000}}\right)\sin \left({\frac {9\pi k}{100000}}\right)\right)^{2}+\left({\frac {1}{20}}\right)\left(\cos \left({\frac {41\pi k}{10000}}\right)\right)^{2}\left(\cos \left({\frac {\pi k}{20000}}\right)\right)^{10}.}$

See more details at: www.ams.org/mathimagery/displayimage.php?album=40&pid=684#top_display_media