Kent Cooper is back this month with a routine to create Lamé curves in AutoCAD, otherwise known as superellipses. A superellipse is a geometric figure defined as documented here.
As he does frequently, Kent authored this routine as a response to an inquiry in the Autodesk customization forum. Read the header of the AutoLISP file for detailed information on what the input parameters are, and after you load the AutoLISP file, the command name is Lame. Thanks for introducing most of us to superellipes, Kent!