pow()

double pow(double x, double y);

void setup() {
    pinLabel(0, "IN");   // set the label of pin 0 to "IN"
    pinLabel(1, "OUT");  // set the label of pin 1 to "OUT"
    pinMode(1, OUTPUT);  // set pin 1 as output

    pinLabel(2, "VCC");  // set the label of pin 2 to "VCC"
    powerPin(2);         // set pin 2 as power pin
    pinLabel(3, "GND");  // set the label of pin 3 to "GND"
    groundPin(3);        // set pin 3 as ground pin
}

void loop() {
    int val = analogRead(0); // read the value of the potentiometer
    double x = map(val, 0, 1023, 0, 5); // map the value of the potentiometer from 0 to 1023 to the range of 0 to 5
    double y = pow(x, 3); // calculate the value of x to the exponent of 3
    int pwm = (int) map(y, 0, 125, 0, 1023); // map the value of y from 0 to 125 to 0 to 1023
    analogWrite(1, pwm); // write the value of pwm to pin 1
}