Not sure if these are 'themes' as such but is this to do with the 64 defining characteristics of the discourse of a Buddha, or enlightened one ?
I know that the Dalai Lama consults Mo divination when making decisions, which employ dice - anything to do with that ? The only connection between 64 and dice I can think of is in backgammon.
Is this anything to do with the game called 'Sho' in Tibet - (tibetan word for dice). Played on a board formed by a circular line of 64 shells. I know that the old Chinese units of measurement used a hexadecimal system ie. based on the unit of 16 - am I getting any closer ?
Confucius ? I Ching - classic of changes based on 64 Hexagrams ? Not sure where the dice come into this though.
Ah sorry to confuse.. That is it.. I was just trying to point to that it was some sort of oracle... 64 hexagram ancient Chinese oracle.. That was traditionally thrown with arrow sticks and more latterly with a coin.... Over to you