The brilliant American computer scientist Donald Knuth has been writing and publishing The Art of Computer Programming since the early 1960s. He hasn't finished yet. In fact what he does is create small chunks of material, he calls Fascicles, and releases them in PDF form before finally collating these into printed volumes.
One of his latest is HERE (Volume 4 Pre-fascicle 5C). I can't pretend that I am able to understand what he is doing, but I can appreciate his playfulness is setting problems to the more serious reader.
Above is a game he includes in the fascicle.
Dominosa is a solitaire game in which you `shuffle' the 28 pieces of dominoes and place them at random into a 7 x 8 frame. Then you write down the numbers of spots in each cell, put the dominoes away, and try to reconstruct their positions based only on that 7 x 8 array of numbers.
The image above is the example he shows.