One of 33 LED output Indicator

[Mike, K8LH]

I agree with Henrik. You could Charlieplex 30 LEDs using six pins or up to 42 LEDs using seven pins. Or add a 74HC595 or a driver IC and multiplex the LEDs. Here's a multiplexed example for 32 LEDs that only requires five pins using my MacMux interface method (below).

Happy Holidays and cheerful regards, Mike