// Taken from functions.scad
//  existing as public domain
//  2015 by Torsten Paul
//  example in OpenSCAD
//  and relicensed as
//  GNU AGPLv3
//  2018 by Quiliro Ordóñez

function f(x) =  x * x/8;

color("green")
    for (a = [ 0: 1 : 20])
        translate([a,f(a),0]) sphere(.3);