ABCD
Pi vs. Tau

[[On the left is a "forbidden"-style slashed circle with the Pi symbol, captioned "Pi". On the right is a "forbidden-style slashed circle with "2Ï", captioned "Tau". In the middle it reads "1.5Ï", captioned "Pau".]]
A compromise solution to the Pi
Tau dispute
{{Title text: Conveniently approximated as e+2, Pau is commonly known as the Devil's Ratio (because in the octal expansion, '666' appears four times in the first 200 digits while no other run of 3+ digits appears more than once.)}}
Conveniently approximated as e+2, Pau is commonly known as the Devil's Ratio (because in the octal expansion, '666' appears four times in the first 200 digits while no other run of 3+ digits appears more than once.)