I am taking this puzzle from inspiration from the Four Fours to get Pi puzzle. The puzzle rules are just slightly different. Here are the rules:
You are trying to get as close to e as possible with only πs used as real numbers in the approximations, and with the following allowed operations:
- Simple arithmetic: +, -, x, ÷
- Exponents and logs as binary operations: $\log_a b$ and $a^b$. You can only take logs of positive numbers.
- The root function as a binary operator $\sqrt[b]{a}$.
- Unary operations: $(\cdot)!$ for integer arguments only, unary negation -, the square root $\sqrt{\cdot}$ for positive numbers, and floor and ceil functions: $\lfloor\cdot\rfloor$ and $\lceil \cdot\rceil$.
Any other operations are not allowed, including double factorials and decimal points. In addition, you can do the following with no penalty:
- Parentheses (for grouping purposes only, no binomial coefficients etc.)
The score will be calculated the same way as in the four fours puzzle*.
Your score is equal to the number of digits of accuracy per operation used. That is, if you got the approximation A by using n operations, your score is
$$\frac{-\log_{10}|e - A|}{n}$$ (adjusted for e instead of π.)
*However, as a side note, you multiply your score by π/n where n is the number of πs used in your approximation.
The one with the highest score will get that sweet green checkmark on their submission.
Hint:
Try to use $$\lim_{n \to +\infty} \left( 1 + \frac{1}{n}\right)^n = e. $$