# Problem 461: Almost Pi
Let fn(k) = ek/n - 1, for all non-negative integers k. Remarkably,
f200(6) + f200(75) + f200(89) + f200(226) = 3.141592644529… ≈ π. In
fact, it is the best approximation of π of the form
fn(a) + fn(b) + fn(c) + fn(d) for n = 200. Let g(n) = a2 + b2 + c2 + d 2
for a, b, c, d that minimize the error:
| fn(a) + fn(b) + fn(c) + fn(d) - π| (where |x| denotes the absolute
value of x). You are given g(200) = 62 + 752 + 892 + 2262 = 64658. Find
g(10000).