I have a math puzzler for fans of the transcendental number, e:
(1+9^(-4^(6*7)))^(3^(2^85)) = e (almost)
is accurate to over 18,000,000,000,000,000,000,000,000 decimal places.
What is notable about this formula is that it uses all the digits, 1-9 exactly once. It does not produce e exactly...