Seems loads of fun, even though computers are involved
The NY Times crossword for the numeral obsessed?
I have this idea for the finding of the first Mersenne Triple Number, awaiting only the finding of the next ~11 singletons; alas, my margins Are large enough to contain the calculations.. but isn't the most fun when - you Find Out but don't tell anyone?
Then, years later - - someone can say, "I knew him, Horatio. A fellow of infinite jest. But humble to a fault. :-/"