There's a system of Chinese fortune telling called the I-Ching. You throw three coins at random, each tails is 2 points, each heads is 3 points. Adding up the 3 coins you will get either 6, 7, 8 or 9. If the number is odd then you draw an unbroken horizontal line on a piece of paper, if it is even, a broken line. The process continues until you have a figure which looks something like this https://www.psychic-revelation.com/images/i_ching_57_sun.jpg

There is 64 possible variations which can be produced this way, called "The 64 Hexagrams" of the I-Ching. Naturally, I am lazy and also don't have any coins, so I just use the Google random number generator to get a random hexagram between 1 and 64.

However, if when throwing the coins, you get either a 6 or a 9 for a particular line, then that line has special significance and is afforded additional interpretation. I'm trying to figure out how to easily randomize for this? So, what additional random number generation could I use to select which lines should get this and which lines shouldn't? Only when there is all heads or all tails is the number 6 or 9, but I'm unsure what odds each line has of being a "significant line" and if it's possible to generalize this to a single or two operations.

Hopefully that made sense.