5 bit binary counter

Using Arduino LEDs and Multiplexing
3

Five-bit counter with auto wrap around to 0

counter++ & B00011111;

If your output pins are on the same port and in a row then something like this

PORTB &= B11100000;
PORTB != counter;

If they are on pins all over the place then extract the bits and use a series of digitalWrites() to set the pins.

Rob