Running LEDs using Adafruit Neopixel

Hi,
I´m working on a project where I need 2 leds distributed evenly along a 60 led strip.
Say led 0 and 29 is on then led 1 and 30 is on and so on.

For 1 leds it works fine:

void loop() {
for(i=0; i<pixels.numPixels(); i++){
pixels.setPixelColor(i, pixels.Color(0,0,0,20)); // White color on.
pixels.show();
delay(delayval);
pixels.setPixelColor(i, pixels.Color(0,0,0,0)); // White color off.
pixels.show();
}
}

but when I add a offset for the second led it does not “overflow” to the start of the strip when the end is reached:

void loop() {
for(i=0; i<pixels.numPixels(); i++){
pixels.setPixelColor(i, pixels.Color(0,0,0,20)); // White color on.
pixels.setPixelColor(i+29, pixels.Color(0,0,0,20)); // Offset White color on.
pixels.show();
delay(delayval);
pixels.setPixelColor(i, pixels.Color(0,0,0,0)); // White color off.
pixels.setPixelColor(i+29, pixels.Color(0,0,0,0)); // White color off.
pixels.show();
}
}
What am I missing?
It might be fairly simple but right now I´m stock and would like some input from you guys.
Thanks.

BR
repsej

What am I missing?

The modulo operator (%)

What am I missing

You have missed reading the how to use this forum sticky post. It will tell you how to post code and to post all the code not just snippets.