Generating an entertaining blinking pattern for a 1D LED arrangement
I want to actuate a hardware featuring a set of 16 LEDs, arranged in a square:

      X   X   X   X   X
      X               X
      X               X
      X               X
      X   X   X   X   X

While I can solve the technical details (timer, bit masking, etc.), I am stuck with an artistic question. 
What would be a good algorithm for generating an activation pattern (over time) which is entertaining for a human observer?

I don't want to go for a totally random pattern, but also not for something too predictive. Any suggestions, especially with compact generator algorithms are welcome.

LEDs are binary (on/off) and single color, but I could install different LEDs of single color (red,green,yellow).
Generating an entertaining blinking pattern for a 1D LED arrangement
===

I want to actuate a hardware featuring a set of 16 LEDs, arranged in a square:

      X   X   X   X   X
      X               X
      X               X
      X               X
      X   X   X   X   X

While I can solve the technical details (timer, bit masking, etc.), I am stuck with an artistic question. 
What would be a good algorithm for generating an activation pattern (over time) which is entertaining for a human observer?

I don't want to go for a totally random pattern, but also not for something too predictive. Any suggestions, especially with compact generator algorithms are welcome.

LEDs are binary (on/off) and single color, but I could install different LEDs of single color (red,green,yellow).